Bleeding of and a little on. I NEED HELP LADIES

why could my bleeding be all over the place? Starting on the 12th I was having what I thought was "implantation cramping" lasted all the way until the 14th. On the 15th I started my period super super light period. on the 16th it then got heavy, on the 17th it was heavy during the day now that I'm settling down and noticing my bleeding, it is very light as well. This is the 2nd month that my period has been doing this. What could this mean? I have been trying to conceive for maybe 4 months.