From Depo to Lo/Ovral, but no period

I took Depo Provera for a year, but decided to switch because I would have either no period or extremely long periods and they were highly unpredictable. I switched to Lo/Ovral prior to when I would have estimated when my period started. I have been taking the reminder pills for 4 days, and I've yet to have a period. Could this be due to the Depo?

[peekawho]

After stopping Depo, it can take up to a year or more to resume regular periods, although most women have some return within 3-6 months.