The Pill questions

So I've been on the pill for about a month. Yesterday I started my new pack and my switched my time taking the pill. I spent the night at my boyfriend's last night and woke up to him kissing me and then that turned into other things. Long story short, we did not use a condom and he is usually good at the withdrawal method. Afterwards, we found a spot on the bed that showed he had ejacatulated a little bit but he didn't know because he thought he ejacatulated just one time and that was the time that we finished, but he had pulled out that time.