Opinions?

So I've been tracking AF for 3 months now since stopping my BC and it's been on the dot regular. So this month after bd'ing all through ovulation, my period came exactly a week earlier than expected. Hoped it may be implantation bleeding at first but after a week of it I'm pretty certain it's AF. So my question is- do I go by this new period date for ovulation, or go by the the old schedule? Also, I have heard good things about the Geritol, do I start that at any time, or wait until around ovulation? TIA!