The "chances and percentages" don't really matter if you are the one who gets pregnant. Say the odds are 1%. For the person who is that 1 out of 100, for them it is 100% no matter what the odds and percentages are.
Your odds will depend on whether you were ovulating at that time, and there is very little way to know if you are. Some women are like clockwork with their ovulation and some are not.
Hate to say it, but the first time I got pregnant I was young....and it was due to something of this nature....
if you are ovulating you have very good chances of being pregnant. there is no way to calculate a percentage.
wait 2 weeks and take an hpt.