Could I be pregnant?

I am on the pill but during my last break from it I only took a break for 6 days but this time I took a break for the normal 7 days. Today (3 days since starting the new pack) my boyfriend pre-came then put it in for a second. I’m worried that because I extended my break this week my body would have needed a week to get used to it but I didn’t wait a week.

I’ve googled it and it says if you’ve started your pack a day late then you are still safe and he didn’t cum in me it was pre-cum but I am still a bit worried.

Should I consider buying plan B?