Help I'm going through a "pregnancy scare"

So my boyfriend and I had sex and we always always use condoms . Also I just got on the pill 3 weeks ago and I'm okay at taking time wise but I take it everyday (never missed) so anyways my Bf and I had sex one time then did it again but without a condom , it was only one or two strokes . Then another time just recently we did it and tried again for a second time then he came but I made him wipe off it completely before he put it in me ..both times were really short . Never came in me we used a condom after he put it in for a sec ..I'm scared of pre cum , and cum left over ? Please give me some reassurance I'm one day late ...but I'm on the pill for 2 ,1/2 weeks now ..