Birth control and spotting?

So Im 23 and started on birth control about 3 weeks ago. The doctor had mentioned that spotting could happen for a few months but I haven't noticed any at all. Long story short since at strong birth control I have had no sex drive. This afternoon I decided that I was kind of horny so my boyfriend and I finally had sex. It was so painful and didn't feel good at all which has never been a problem before and when he finished I went to lay down and there was blood all over his white sheets which has never happened before.  I ran to the bathroom and wiped and there was just a small amount of blood and nothing since. Is that I'm so embarrassed he kept saying it was okay but I just left while he was taking a shower and took his sheets with to clean.  Is bleeding during sex normal when taking birth control?? Also how do I get blood off of white?? 
Sorry for the tmi but I am petrified.