I have a retroverted uterus and with both previous pregnancies the placenta was on the front so baby very much hiding. First pregnancy I felt nothing I could be sure of until 17 weeks, second at 15 weeks. This time placenta is on the back and I have just been lying here feeling the first little flutters tonight at 12w4d (measuring 13 wks). What I'm feeling is very faint but I'm far more sure of it as I know what and where I'm feeling far better this time. It's just very slight little bumps and squirms. Love it!