5 days late, negative tests

Hi there, I came off the contraceptive pill on 8th Feb. First day of my last period was 9 Feb. I have always had regular periods when on the pill. 
I was due to start my period on Thursday 9th March. I did a test the day before because I have been so tired, had a bit of sensitivity in my breasts and nipples and been extremely bloated and a couple of times I have felt nauseous. It was a negative result. 
However, I have been having period pains for over a week too so I have been fully expecting to start my period and have put it down to coming off the pill and my cycle being all over the place.
This morning I took two tests and again both negative (4 or 5 days late now). Still getting a few period type cramps, back pain and very tired.
We have been having unprotected sex twice a week and two of those occasions were on my fertile days ( according to this app). 
I don't want to get my hopes up but I have never been this late for a period before - even though I have been on the pill for over 10 years, they have always been regular. I'm 31 so I hope it's not early menopause! Any ideas? Should I test again?