Pregnant or weird period???

Samantha
Okay so every period I've ever had a week before my period arrives I get pms symptoms. My boobs will be sore  up until the day I start and I will cramp off and on. Then the first day of my period I experience cramping so bad I have to take Tylenol for it. I also have very heavy bleeding the first day and medium the second then it gets light. 
This month I haven't had any symptoms other than being weepy. Glow said I was supposed to start yesterday and I did but it wasn't my normal period. I used a tampon yesterday for 6 hours and only one side had blood then I used another one last night and left it in while I slept. It was in for about fourteen hours and was only half full. Anytime I use a pad there is only like a drop. Could I be experiencing implantation bleeding? Me and my fiancée have been trying to conceive for three years.