Missed period advice?

Hello ladies I have a couple of questions!

I’m now 14days late on my period I’m usually very spot on with coming on my period and im never usually drastically late just a day or 2 max!

Im not on any contraception and have had unprotected sex with my boyfriend we we’ve been trying for a baby.

I’ve done tests but they have come back negative?… is it possibly my HCG levels are to low and not showing or to early in the pregnancy IF I was to be pregnant.

I’ve had mild cramping but no spotting etc! I haven’t been stressed or had a change in my diet with food or fluids or take any medication.

When I was pregnant with my son it didn’t show I was pregnant till I was 4/5weeks gone could I be in a similar situation? & with him I fell pregnant on the last day of my period so my ovulation isn’t the standard cycle as such

Any suggestions would be greatful thankyou in advance 😀