I had my son 6 weeks ago. My boyfriend and I decided to have sex last night since he'll be leaving for a training with the military tomorrow. I started my birth control this Wednesday. I know I'm supposed to keep it safe for a week because the meds have to get in my system.. But the first round we used a condom,the second round we didn't use any he pulled out of me and came on my vag. Can pregnancy happen this way?Just curious.