implantation bleeding?

The last time I had sex was January 26. I started spotting  a bit today but my period isn't supposed to start go like 4 more days. Last period started the 12th of Jan and ended the 16th. Is it possible to be implantation bleeding even though I haven't had sex in like 2 weeks? Or just my period being off?

[remar]

I think your period is just off. Usually implantation bleeding happens before two weeks.

[KeeLolo]

If you have a regular cycle and You had sex on the 26 of Jan and if my math is this would of been around your fertile time. and if you ovulated fertilization and implantation takes place about 8-10 days after you ovulate....so if you were pregnant you should of been able to test about Feb the 3rd or 4th. So i think that this may just be your cycle is off..Hope this helped!!!