I am not sexually active right now and yesterday i started having pain when i walk and sit. i have what looks like three canker sores on the lip of my?

Herpes?: It could be herpes, but don't freak out about it. Have it examined while the sores are still there. If it is herpes, it is incredibly common and can be suppressed with medicine and contained by appropriate precautions.

See MD: There are various causes for these ulceration. Viral like herpes, autoimmune like lichen planis, to bacterial as in STD. You need to have your primary care physician, OB/GYN or dermatologist examine this area. They can determine cause and provide immediate and/or long term care. ASAP.

Herpes simplex virus: A number of factors can trigger the HSV-2 virus, including stress, fatigue, other infections, fever, menstruation and GI upset. There is no cure for cold sores. However, some medications may relieve pain and soften HSV crusts on the skin. (E.G. pencyclovir cream). The healing is within 7-10 days.

See your MD: asap. If you already have a current OB, you rather see an OB. Some insurance requires referral first from your primary provider so be aware of your ins provisions. Be healthy.