Can anyone RELATE???

So on the 13th of april i started spotting light brown blood it lasted 14 days. Being the 27th when it finally stopped. It was very light hardly enough for a pad. It was like watery cm. Anyways i started having mild cramps and then they were gone and it stopped then 3 days later it starts again. Can anyone relate or has anyone experienced this? And if so what was the reason..... My periods are irregular but they've never been like this. I´ve taken tests but there neg. So i dont think its implantation.with my 2 son's i never experienced implantation bleeding just the cramps....CAN SOMEONE PLZ TALK TO ME.