What Causes Absent Periods With Negative HPT After An Abortion?

Hi, i'm almost 40 years old and had my pregnancy terminated at 6 weeks (from conception). This was my first pregnancy. It is now almost 22 weeks later and i've had no menstruation. I've had -ve pregnancy tests at home and at the gp's, no signs of infection, discharge, or pain. My FSH and LH results done last month are raised and have been repeated again today. ( FSH 25.6 LH 28.7) Please can you give me a clue as to what is or isn't happening with my body.