Paranoid about being pregnant

My boyfriend and I had unprotected sex twice last night and he used the pull out method. It's two days after the end of my period so I know there is a low chance of ending up pregant, but I just can't help but think that he didn't pull out in time. I really don't want to take plan B because I took it last month when I probably didn't need to, and I had horrible side effects. I'm just paranoid I might ovulate early or something, but at the the same time I highly doubt it because when we had sex I didn't have any cervical mucus which I usually experience around ovulation. Do you think I should be worried, or am I in the clear?