Implantation bleeding or not?

Last month I missed most my birth control, as the holidays had me all over. I remember being on my period on nov. 17th. I haven't had sex in months and it just so happened this month on the 13th I had intercourse without protection. I normally start around the middle of the month as I had been on been on birth control and it coincides with my normal cycle anyways. I realized I hadn't had my period and I took a test all the ones I have taken had really faint lines that i feel now could possibly be evap lines because today I started spotting. No cramps ect, no bloating. Also i normally have bloating breakouts and a white discharge before my period and this month that was all non exsitent. If I go by my normal cycle I'd be two weeks late anyways. I'm just curious as to what others think? My second pregnancy I had implantation bleeding as well...