I’m so confused

Confused 🤷🏻‍♀️. So let’s start with this I Was directed to take Letrozole 2.5mg on CD 3-7 on CD 17 I started spotting this was sooo light that it was only present when I wiped and there was none on the panty liner ! It was light pink . Later that night it go darker but still pink not red. CD 18 brown spotting in panty liner and I could see the flow a little in the toilet but when I wiped it was pinkish Orange. Later that night it went to a brown mixed with red magenta. CD 19 a red and could see flow in the toliet tiny clots and one clot the size of a dime. Called the Doctor they said it still could be Implantation but I told them I was sure it was AF. So I tested with first morning urine on CD 20 and there was brown blood but still spotting negative HCG test. So I counted CD20 as CD 1 of a new Cycle. I’m now on Cycle day 2 and that spotting is gone ? Like when I wipe its light brown but it’s almost gone ? So should I just start 5 mg Letrozole Tomorrow and continue assuming it’s AF? My cycle is heavy usually so I thought the meds made it light.