Implantation?!

I know this isn't about pregnancy tests but I've posted this a couple times already because I want opinions or reassurance or idk what I'm really looking for, answers I guess? So I haven't used opk's, planning to next cycle and can't really chart because of horrible sleeping patterns (insomnia) and night terrors. My cycles are also irregular with shortest being 27, average 33, longest 41. Last period was the 23rd and stopped spotting on the 28th. I do feel like my fertile days were from the 2nd to the 6th because on the 3rd and 4th I had EWCM, slight cramping and major cramping on the 4th especially, with high soft cervix (couldn't tell if it was open, also sorry if most of this is tmi) on the 7th after peeing, I wiped and there was pink-happened twice that day (I've never wiped and there was pink, except for the beginning of my period of course) and not since then. Yesterday for 12 hours I started to have this pulling-pinching feeling on my right abdomen, I've never had this before-and it was like cramps but lighter? Sometimes it hurt but most of the time it was like small twinges that contracted to the middle of my abdomen and lower back. It even did it when I layed down? I BD'd the 1st, 2nd, 3rd and tried to on the 5th but just as he was about to ejaculate (tmi sorry I know) he wanted to take a 'water break' and didn't finish. Any advice?? I've read on a lot of forums that implantation can happen as early as 3-4 dpo, this was told to women by doctors. I'm on cycle day 20 right now and like I said-never experienced this. So???? Anyone else too? Any advice? Opinions?