Uh I’m really confused

I had a baby girl in February. Bled from the birth (lochia ) & then had a cycle right after I bled from the birth all in February. March me & my child’s father had unprotected sex . I got a bfp I also had 2 BFP’s with the one step purple & white dollar general tests

Then a BFN the next day with FMU at 5am

So I thought .. ok a chemical pregnancy( I had one before we conceived our daughter & I came on right away after ) . It’s April & still NO PERIOD AT ALL 😑 like what’s happening? I’ve even taken a clear blue digital & it said “Not pregnant “ . I only feel dizzy & nauseous time to time & exhausted but I also have an almost 2month old who wouldn’t be exhausted right ? .. ANY can inquire any ADVICE or EXPERIENCE after a chemical that didn’t come on right away ? Any help is welcome 😩