From what I understand, even if your flow is light, you may still be ovulating. You need to be gushing to be an indicator of ovulation. That being said, that doesn't guarantee that you are ovulating. katrina is right though, if you do bleed every month, you could start charting you basal body temp. every morning. Start from the first day of your bleed and count as day 1. That way, you will have something concrete/visual to look at. Also, before you take meds. your hubby should be checked as well, as it may not even be you. (especially if you do have af every month) Why spend tons of money and waste time if there's no need. It's the easiest place to start with.
Keep us posted, and I hope this helps.
Rose