Sometimes it takes a while for your cycle to get back to normal after coming off of birth control. How long has it been since you stoped?
Yes there is some medicine that you doctor can prescribe you to jump start your cycle to have a period, but I think that you have to have not had your period for some time.
What else have you done to ttc. Do you chart your temps? That is a good way to let you know if you are ovulating. It shows you a pattern of your resting temperature. After ovulation, your temp goes up about 1/2 a degree and then goes back down when af comes. A good site to go to for this is fertilityfriend.com. They have a lot of tools that are very useful.
Feel free to ask any questions, there are a few girls on here that have been doing this for a while.