Idk.. implantation bleeding or light period?

Heyyy.. so me and my boyfriend just started ttc ... my periods are normally regular.. uk I fill up about 4 pads (I use more , but technical wise I FILL bout 4) ... my period is real light . I probably havent even filled a pad (I change my pads every so hours cuz I hate the old blood smell) .. but my period has been light and dark .. im on day 3 .. im also a petite girl im like 5'0 & 105 ... this is honestly a FIRST.. also I only really see most of the blood when I wipe..