I had an unprotected sex with my partner on the 19th of January. He didn't release into me cuz he pulled out on time. After two weeks I started having pre-menstrual symptoms I usually have before my period comes. My menses was to start on the 3rd of February (this month) but I didn't see it. After 5 days (8th of February) Precisely in the afternoon, I saw a light red blood (like the one you'll see when it starts) after I wiped. What actually got me concerned was that it didn't flow throughout that day (which is VERY UNUSUAL). The flow started the next and I saw little clots . I used two pads for the whole 24hrs. My pad was full and this flow lasted for two days (my cycle lasts for 5 days). Could this be implantation bleeding? I'm really confused cuz I'm not sure if he had a pre-come.