TTC for long

My fiancée and I have be trying to conceive for long now ,like his not around Nigeria whenever he comes around ,we are always together till he goes back ,😔at the end always negative

September we were together stroke this month of October after my cycle has ended he travels back

I tested September to be negative

On this October I tested negative on 9DPO and 10DPO

Am tired and confused

Cos I have never had abortion or take any pills nor be pregnant before in my life

Wat coukd be causing this delay 😭😭pls guys I need ur help what should I do