Period or implantation ??

Ok so(March 24) yesterday what I think/thought was my period it was bright red and light how it usually starts off and ODST it’s still light , it’s usually heavy the next day... and it still bright red but barely anything coming out. I had sex on the 15 and 18 but both days were protected and the condoms did not break and I also put water in them to check if there were any leaks which there were none. I have PMs symtoms . But could it be implantation .. notbtrying to be pregnant 😔. My period was actually suppose to come today (March 25) please help