Implantation bleeding and period

Ok so I'm supposed to get my period in 4 days and I've been having small cramps and sensitive boobs but I started bleeding last night not regular bleeding it was extremely light which sometimes would happen before I get my period but it's day two today and I was bleeding alittle more earlier but it was still light so I put a tampon and I took it off just now and I barely bled at all it almost looks pink and I'm getting alittle worried because I had sex on Saturday without protection but he did pull out and I saw him I am in one stress because of school but that's nothing I just hope it's not implantation bleeding because I honestly don't know what exactly is going on