So I'm using one of the tracking apps. My cycles are usually 28-30 days long. Last month I ovulated (according to the app) at CD17, a day after my positive OPK. Cycle was 29 days. This month the app says I ovulated at CD19, three days after a positive OPK and I guess I'm not convinced. My BBT has remained high (only one small dip since the app located ovulation. I'm now on CD30. No sign of AF. Time to POAS or should I wait?