on Feb 13th I went through a chemical pregnancy at 4 wks. It was my second miscarriage. had one back in Sept at 7wks with d&c; at 9wks. so I'm not the one to wait till my missed period to take a hpt. AF is due in 3 days so I couldn't wait any longer. took a test at 530pm and it was positive!!! here is my calendar and the days I was supposed to ovulate and the days me and the hubs did the deed. hoping this helps someone!!!