Yes it could... Anytime semen gets near you, enters you during your ovulation period! It is a tricky one as now you will be worrying all the time. If you font want a baby then visit your GP fir ammediate advise, if you think falling pregnant wouldn't be the worst thing in the world right now then speak to your boyfriend. It's a 50-50 chance I guess and you won't be able to test straight away. I hope you get the result you really want.
It is possible, wait until the day your period is due at least and take a test.