Hey ladies!

My apologies if there is an obvious answer to this. I had my IUD removed Jan. 4th, got a blazing positive OPK on Jan. 18th and am starting what I believe is my period today, Jan. 31. My question is, at what pointed am I considered to be “on my period” and not just spotting? I have spotting leaning towards the heavy side, a liner isn’t enough protection and a pad is overkill. Would today be considered CD1 or would you say I’m spotting?

Thanks in advance!