Pregnant while breastfeeding?

Has anyone gotten pregnant while breastfeeding and taking the mini pill? I started the mini pill about a month and half ago. My daughter is 4 months old, exclusively breastfed.

I had one period 5+weeks ago.

So technically my period is a little over a week late now and I just feel off. My boobs are hurting like they did when I found out I was pregnant with my daughter, but it's hard to tell if that's just from nursing or not.

I have taken a test and it was negative. However, with my daughter it never showed up on a test until I was two weeks late.

It has to be extremely unlikely to be pregnant right?! TIA