My boyfriend and I have been together for a while, to the point where I hold my whole trust in him, however I'm not sure what to do in my current situation. Him and I have been intimate with one another on several occasions and of course we use a condom each time we decide to engage in sex. However, this time under my bad judgment, I allowed him to enter me without a condom. It wasn't for very long and was only for the sole purpose of experiencing the difference. He told me that he made absolutely sure that there was no precum present, he had urinated prior to us doing this, and he also has a history of not finishing (ie. (on a different occasion) It spent 20 minutes between giving him oral and then a ha****b to which for the first time ever, I saw precum come out of him. He also mentioned that he could feel it come out? I myself though am not taking his word on just that alone. 

One thing that concerns me the most though, according to the Flo app I have (which for the most part is pretty accurate), it said that day that this all occurred was the day of my ovulation. This has all occurred over 24 hrs ago and I am, regardless of whether I am pregnant or not, going to purchase Plan B, to calm my nerves and be more careful in situations like this in the future. 

I am aware that regardless of how long he had it in, there is always a chance of pregnancy with/without him finishing. In a sense I feel tremendous guilt for not trust him, but I need to think about myself and our future first, and I know we are not prepared for this big hurdle. 

I myself am just curious what you all think, is it just my nerves or is there a serious chance that I could be pregnant?