Was I too early?

I was told to call the first day of my period. They say to call when you have full flow, not just spotting. Well I had enough that I needed a tampon so I called and set up my day 2 ultrasound and bloodwork. Now, the flow has slowed down! I’m kind of just spotting. What if I called too early? Will it make a big difference in the testing or with starting stims?

A little background- I did my first cycle in March and had a BFN. I stopped the progesterone and had a period start about 4 days later.

My periods have always been pretty light so I really thought it was starting but now I’m doubting myself, it seems like spotting.

Anyone have any advice?

UPDATE: I went in for my baseline. When I spoke with the nurse later in the day I told her I thought I might have called a bit early and that I think I was actually day 1 on that day. She said everything looked perfect to start so no big deal. Day 2 of stims today!