First Cycle of Clomid. OPK Progression??

So I took my first cycle of Clomid this month. I'm on day 13 of my cycle now. But I still keep getting the same color negatives on my OPKs. I don't even see a progression color from the days before. I mean, this app says my first fertile window day was yesterday. And this app says my ovulation day is on the 19th. But if I started my period on February 3rd, wouldn't my ovulation day be tomorrow? I just hope I get a positive OPK soon. I'm having sex everyday with my husband and using Pre Seed starting last night. Anyone else been through this?