Hello doctor, my last period was between 9th August and 12th August. I had protected intercourse between 25th August and 27th August. However, my boyfriend wore the condom inside out. We realised it and wore it again properly before sex and maybe a drop of precum would've been there. My period was due on 9th September but it got delayed. I took urine pregnancy tests on 11th, 18th and 24th September (first urine sample in the morning) and all of them were negative. I started to bleed on 24th September afternoon which was the same like my period that occurred previous month and it ended on 28th. I took a pregnancy test on 28th morning as well which turned out to be negative. Is there any chance for me to be pregnant. Can implantation bleeding look like period?