Hello, I would be happy to help you with your question.
Most likely your symptoms are related to your cycle. Breast / nipple tenderness and mid-to-late cycle pain related to ovulation and ovarian cysts. This is the most likely explanation. It would be too early for pregnancy
related symptoms. The question of STD's should be addressed with your doctor because if there is concern about exposure, regardless of your symptoms, then you need testing.
I hope that this helps. Good luck and thank you for visiting.