Negative test/No period

Sa

I’m so confused. I have never in my life missed a period and I’m very regular in that, I’m either right on time or up to 2 days early.

I haven’t missed my period yet, but I’m 2 days late.

Husband and I did have sex in my fertile window. I have the SUPER early tests (detects at 10miu or something like that instead of the standard 20-25). It states it can detect a pregnancy only 2 days after implantation.

I have taken multiple of those tests and they are all straight negative.

I don’t even feel like I’m about to start my period. I just keep getting a pulling sensation in my lower stomach and my lower back hurts. Just like in my last pregnancy 5 years ago.

I’m not under any stress, haven’t done anything different, but my period just will not come.

Does anyone have experience with those extremely early detection tests? If I was pregnant, I feel like it would’ve come up positive by now.