Am I pregnant?

Had sex about 3 weeks ago with a condom but as I got off we noticed the condom fell off. Bf claims it was on all time but as I went to climb off him my leg hit it. I did feel something wet on my leg near my knee. I got my so called period the day after <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a> said I would but its not like normal. Day one was heavy but day 2 and 3 were barely there.period last 6 days this one all finished by day 4.I usually have really regular semi heavy periods every month. Do you think this is an irregular period or could there be a chance of pregnancy and its just spotting?