Is it normal, or abnormal and I'm just ignorant?
About two weeks ago I lost my virginity and began having sex with my new boyfriend for the first time. I am 19 years old and am not on birth control as I had not been planning on becoming sexually active anytime soon. The first time we had sex I did not bleed (I am very active and healthy and suspect I tore my hymen during a sporting activity). I became worried because we had only used the withdrawal method and purchased the Plan B pill about two days after intercourse had occurred. A week later (late afternoon December 14th) we had unprotected sex again using the withdrawal method.
On the 16th of December at work, I noticed that I was experience some vaginal spotting had actually soaked through my underwear (it's been a brownish color and is brown or pink if I press toilet paper to myself while using the bathroom) and lightly stained the shorts I had under my uniform bottoms. I had my period on December 1st so I know it was not that (I am very regular and my periods are very heavy).
I have never, ever bled outside the range of my menses so I am very concerned. I have searched the internet for answers and nearly had a panic attack when I read you could have spotting as a sign of being pregnant (implantation bleeding). We had not used protection and after using an ovulation calculator, realized that I may have been ovulating at the time. I also read however, that "some spotting is nothing to be concerned about the first few times having sex."
I am entering my fourth semester at my university and am a full-tuition merit scholar majoring in pre-medicine/biology. I have many plans for the future and am not looking to get pregnant for many years to come.
I am very worried and would appreciate any advice that could be given on this matter. Thank you very much.