According to Dr. Carolyn Alexander from Southern California Reproductive Center, there are a few different factors that could play into your ability to get pregnant during a certain amount of time, but if you're healthy, there's a guideline. "If under 35 years of age with regular periods, normal anti-mullerian hormone (AMH), and taking prenatal vitamins, the general rule of thumb is one year of timing intercourse to ovulation," Alexander says. She notes that AMH is a blood test that can check the health of the ovarian egg reserve and many patients, after years of trying, wish they had taken test sooner.

If you're over 35 years old, you have less time to try before reaching out to a doctor. Alexander notes that six months of trying to get pregnant is the guideline for couples who are over 35 years old. After that, it's time to "seek evaluation by a board certified reproductive endocrinologist," Alexander says.

No menstrual cycle is exactly comfortable, but if you find that yours are really painful or that intercourse is, too, Alexander says this could be a red flag. "Painful menstrual cycles and painful intercourse can be signs of endometriosis, which can impair fertility," she says. According to Mayo Clinic, one third to one half of all women who suffer from endometriosis are infertile.

"Untreated chlamydia can hurt the fallopian tubes, which would impact the ability of sperm to get to the egg to fertilize it," Alexander says. Levi agrees and notes that a history of sexually transmitted disease could be a red flag as you try to conceive.

When asked about STDs affecting fertility, Davis says that they definitely can. "Chlamydial infection may be subtle and go undetected for a while. The longer you have it without treatment, the more potential damage," she says. "Gonorrheal infections usually cause more symptoms. If you are treated, a test of cure is needed to insure it has cleared and partners need to be treated. Infections cause scarring and they can close the fallopian tube or impair mobility. Repeat infections increase the chances of adverse impact on fertility."

If you've had any pelvic surgery, you might want to talk to a doctor. "Prior surgical treatment for an abnormal pap smear, such as a cone biopsy or LEEP procedure, could be causing an issue with the sperm ascending through the cervix," Levi says. He also notes that any prior uterine, tubal, or ovarian surgeries should be mentioned to your doctor, as well as surgery for a ruptured appendix or surgery for endometriosis.

Even having ovarian cysts removed could be a red flag. According to Davis, that kind of surgery can affect fertility by potential scar tissue that forms after any surgery, or if it was an ovarian cyst related to endometriosis

Not many people have a perfect cycle, but if yours is really off or you're missing periods completely (but don't have a positive pregnancy test), there could be a need for intervention. "Irregular cycles and/or missed periods is likely a sign of an ovulation issue," Levi says and notes that irregular periods can be the cause of other things, too. "A regular monthly period is an important part of determining the health of the reproductive system. Irregular periods can be a clue to thyroid issues, high male hormone levels, high prolactin levels, or abnormal FSH or estradiol levels," she says. "Polycystic ovarian syndrome (PCOS) can also cause anovulation and thick uterine lining that may put a woman at risk for pre-cancer cells."

No matter how long you've been trying, if you've previously dealt with pelvic pain or pelvic diseases, you might want to talk to a specialist. "A history of endometriosis or any chronic pelvic pain should point towards a referral sooner rather than later," Levi says. "Pelvic infections and a history of pelvic inflammatory disease (PID) are also red flags."

Not all fibroids poise an issue and Alexander notes that they can be treated differently from woman to woman, but they are something to take note of. "Depending on the location of the fibroid and menstrual flow, they can affect fertility," she says. "Occasionally, fibroids can be located in the uterine lining where a pregnancy would like to go and it impairs the blood flow there. They can distort fallopian tubes, compromising the ability of egg and sperm to meet." Alexander says that a heavy menstrual flow can be a clue that the fibroid is affecting the uterine lining.

Davis agrees with Alexander. "Fibroids that are in the endometrial cavity (submucosal) definitely effect fertility," she says. "Fibroids in any other location, the impact is harder to determine. Studies suggest fibroids greater than 5 centimeters have an impact. However, we still need further studies."

Lea von Bidder, co-founder and CEO of Ava, a fertility tracking bracelet, tells Romper that if your cycle seems to be getting shorter, it could be a sign of declining fertility. "If you're worried about this, it's a good idea to start tracking the second phase of your cycle, the luteal phase, which begins after ovulation and ends when your period starts," von Bidder says. "It should ideally be 12 to 16 days, but if it's less than 10 days, you may have a hard time getting pregnant without some extra help."

"Your vaginal discharge plays a very important role in helping you get pregnant," von Bidder says. "It nourishes and transports sperm on their journey to the egg and as your body gears up to ovulate, increased estrogen levels change the quality of your cervical mucus." This fertile-quality cervical mucus often looks like egg whites, but it can also look watery. Von Bidder notes that if you don't notice much cervical mucus, especially in the middle of your cycle as you approach ovulation, it might be harder to conceive.

According to von Bidder, it's normal to see a little spotting in the day or two before your period, but if you notice consistent spotting in the week or two before your period, it could be a sign that your progesterone levels are low. "Progesterone nourishes the uterine lining, and without enough of it, it can be very difficult for the egg to implant in your uterus," von Bidder says.