Boyfriend doesn’t seem to think it’s possible

Minor Venting — need advice. So I may be pregnant (haven’t taken a test yet, but my period is 12days late) but when I brought it up to him he just seems to think it’s impossible that it happened since we used a condom.. (we were also half asleep lol) My emotions have been allll over the place and I have had super bad heart burn/indigestion ... I dont know if he would be mad if I did end up pregnant but it kind of bugged me. We’ve also been together for 4 years.

No we aren’t actively “trying” but things happen. Right?

like is it possible it did actually happen? How does one calm a guy down when that kind of thing happens as a surprise...

I hope this makes sense cause I’m exhausted right now and just needed advice/ to rant.