2 weeks late!

Heya, Hoping for a little advise...?

I'm two weeks late on my period, Its our first month ttc so just starting to understand ovulation, symptoms etc.

I've done 5 tests all spaced apart, first an second test were blue die tests an there was a vvvfl on the second, but the last 3 were all a negative, and used pink die tests, so thinking the 2nd was poss faulty? Last week I was so bloated an constipated, and for the past 2 an half weeks I've had a dull ache/pain in the womb area, have been struggling to get out of bed every morning (which is not me at all, normally a very early riser) nipples are very sensitive, which have never been before.

I was taking the contraceptive pill before we started trying, but even when I wasn't on the pill my periods were always on time an the same type of periods, never been late or suffered with bad pains being heavy etc, always normal.... thinking I'm either going to have a really bad period or.... could it be.....?

just have no idea! Picture shows last period came off on 17th sept... ovulation may not be right as i was due on 10th October