Implantation bleeding?

I’ve been spotting brown discharge Thursday- very faint today and having intermittent mild cramps. No other symptoms.

Usually my periods spot the first day then I’m very heavy the next and almost immobile from the severe cramping and nausea.

Am I having implantation bleeding? I had my second IUI on 1/10/22- they told me to test on 1/24 but last month AF started 2 days before I was supposed to test and I’m usually pretty regular.

I took a test this morning and another BFN.

TTC for over 2 years and just started fertility treatments in December 2021. Thanks in advance.

Someone please give me some insight.