Period after IUD

Copper IUD. Removed first day of my period. Super light, barely bleeding, looks like it's over on day 5. Last 2 days been just beige "tissues" not blood in the cup. Tmi I know

With IUD it was heavy,particularly day 3and 4.7-8 days long.

With the changes in period length I'm assuming its gonna change my ovulation time?. I plan on testing daily anyways, how often in a day do you test opk? Just the morning or 3x a day? I did test last time and we got pregnant but I never truly got the "positive" they say is darker test then control. Just faint lines.