Am I cumming or do I have to pee??

So me and my boyfriend of 5years just started having sex together three weeks ago (he took my virginity). So we are in missionary position and he's going at it 😍 and I start to feel like I'm about to pee on myself so I tell him to stop I need to use the bathroom... well I got to the bathroom and couldn't pee at all. lol I was so cofused.. was I about to cum? 
(Since then I've been making sure I go pee before)