BFN too early or still possible

So we aren't trying to conceive, but we aren't being exactly safe, if we get pregnant it's not a big deal but we aren't actively going out of our way lol. (Pullout)

With my first pregnancy I tracked CM for a long time, and knew right away I was pregnant.

Currently I'm 11months postpartum and I have had periods since 4? Months I think.

I have a long cycle, 35 days, my period is due in like 6 days, past couple weeks on and off I have had nausea, two BFN tests, and cm SEEMS to be doing regular before period things. Its creamy and sticky. I assume it's either

A) too early to test

B) not pregnant

If its B, I'm bot sure why I'm nauseous, google just tells me its food poisoning or pregnancy 🙄 I was just at the dr for a UTI which I had all symptoms but I think I went in too late and it came up negative too.

She asked if pregnancy was an option, I said no but we did have sex on a EWCM day so now I'm not so sure 😂.

Any similar experiences?

eta: my diet hasn't changed at all. No medications except prenatal as I'm still currently nursing.