Credit: CC0 Public Domain

DEAR MAYO CLINIC: I'm 19, and I think I might have a yeast infection. Or it could be trichomoniasis. My symptoms are vaginal odor, unstable periods and pain during sex. I don't feel comfortable going to the doctor about this. Is it safe to try an over-the-counter yeast infection treatment first to see if that works?

ANSWER: It is understandable to have some reservations about discussing personal topics, such as sexual health and vaginal issues. But to safeguard your health, it's extremely important for you to have an evaluation with a to identify the cause of your symptoms and determine the best treatment. Don't try any over-the-counter remedies without consulting a health care provider first.

In sexually active women, symptoms such as vaginal odor, unstable periods and pain during sex have a wide variety of potential causes. As you mention, it's possible you could have a vaginal . This fungal is quite common, and it often can trigger vaginal pain and soreness. Odor is not a typical of a yeast infection, however, and a yeast infection doesn't disrupt menstrual cycles.

The symptoms you describe also could be due to a sexually transmitted infection. The one you mention, trichomoniasis, causes foul-smelling vaginal discharge, genital itching and painful urination. But other sexual transmitted infections, including herpes, chlamydia and gonorrhea, can cause similar symptoms, too. Sexually transmitted infections are common, and they are increasing in frequency, especially in young people. Half of all new cases of sexually transmitted infections occur in people ages 15-24.

Even if you weren't having symptoms, you still should be screened at least once a year—and prior to sexual activity with a new partner—for chlamydia and gonorrhea. That's because these two sexually transmitted infections don't always cause symptoms in women, and they can lead to long-term health concerns, including infertility, if not treated. In addition, having an untreated sexually transmitted infection can increase the risk of getting another one, such as HIV or syphilis, if you are exposed.

Your irregular periods may or may not be related to your other symptoms. For example, thyroid and pituitary gland disorders can lead to unpredictable menstrual cycles. And irregular cycles in conjunction with pain while having sex could be caused by a disorder of the vagina or cervix, such as cervical cancer.

Cervical cancer screening is recommended, beginning at age 21, for all women. Because of your symptoms of irregular bleeding, though, that testing would be recommended now. And if you haven't already had it, you should also be vaccinated against HPV because certain strains of HPV can cause cervical cancer.

To sort through your symptoms and what they mean, you need to work with a health care provider who can thoroughly evaluate your condition, arrive at an accurate diagnosis and recommend treatment. In a case such as yours, it would be best to see your primary care provider or gynecologist.

Other options include a public health clinic or a clinic specializing in women's health. If your symptoms are causing ongoing problems that you feel need immediate attention, consider going to an urgent care center. If you are a , most college campuses have health centers where students can be evaluated for sexually transmitted infections. Or if they don't offer that service, they likely will be able to provide you with a list of resources available in the community.

Although talking about issues related to may be uncomfortable, keep in mind that these conversations are common for , internal medicine and gynecology health care providers. Discussing and managing symptoms associated with sex and reproduction is an important part of their training, and they can make sure that you get the care that you need.