What Causes Sharp Pain In Lower Part Of Vaginal Bone?

I have sharp pains in my lower part, right above my vaginal bone whenever I move things with my inner leg, walking up stairs, if I hold my pee for a while, if I carry things, etc. I had a miscarriage a year ago but don t know when these pains started. I have no insurance and can t afford it right now, what is it? What should I do? Do you think it could be serious? Please help! It hurts.