is it possible to get pregnant from Pre-cum, even if he wasn't close to finishing?

My boyfriend and I had sex a couple of times without protection. But he put a condom on like 2 minutes after we started. My period is 3 days late, I'm on day 41 of my cycle (My cycles are typically on the longer and irregular side). I'm worried about the possibility of pregnancy, but I also know there are other variables and as a college student I know lots of stress and fluctuating diets, which both apply to me, can cause late periods too. Any thoughts or suggestions? I'm pretty anxious about it, but I want to wait a few more days before getting a home pregnancy test