18 days late & 1 BFN

Bree

Hi girls, I’m a bit confused as I’m 18 days late for my period, I’ve never been this late, the latest I’ve been is like 4-5 days and that’s happened once, I was due for my period on 31st of March, now I usually bleed for 6 days every 28 days, my last period was the 5th of March and I only had spotting which was a pinkish colour and only when I wiped and that was for 3 days and the other 2 days I was sort of heavy bleeding, which I found rather strange cause I’d usually bleed heavily for 6 days, I did a pregnancy test on the 12th of April and it was negative, only symptoms I’ve had is a bit of nausea, very fatigue with no energy, shooting pains on the left side of my stomach and the obvious no period, so my question is has anyone experienced the same kind of thing or has any help or advice they can offer me.