What Are The Chances Of Pregnancy Through Non Penetrative Sex?

So, I have been on the birth control pill for 3 years. In this month, I missed one maybe two pills (never back to back) put I took them the next day. I was on my placebo week and my boyfriend decided to ejaculate on my back (we did not have sex). The problem is that when he ejaculated, there was a little that might have dripped down. I don t know if it got in my vagina. I am worried about if I am pregnant or not. Is there anything that you could tell me that would set my mind to ease?