So I had sex for the first time four days ago. My boyfriend and I used a condom,it didn’t break and he pulled out before he ejaculated. However today,I got some seriously heavy bleeding and I thought I was getting my period early. But it was so much heavier than my regular period and it only lasted a few hours,after which the bleeding stopped. I’m seriously worried that I could be pregnant,or if there is something else wrong with me. Help?