Feeling confused on my cycles

Soraya

So I saw my Obgyn last week. We have been trying for awhile. I just turned 35 he said if it doesn’t happen by June to come in and we will begin testing etc. I told him it’s been a little challenging bc my cycles range from 23 days to 30. But today on the 21st day of my cycle I’m having light spotting tough boobs the whole thing. And I’m discouraged bc it appears my period is starting. 21 days in!!!! Last time we had sex was 7 days ago. I don’t think it’s implantation bleeding right? Isn’t 21 days short?? Just confused if I should call him and let him know or if this is normal.