I am 39 and trying to get pregnant. A few days ago I had a one time discharge of what looked like a dime size blood clot. Its 9 days until my period. Could this be a sign of pregnancy?

Unlikely. The first manifestation of pregnancy is usually missing your period.

Unlikely. The first manifestation of pregnancy is usually missing your period.
But I have heard of women that have a period in the beginning and through out pregnancy

Yes, some women have leakage during pregnancy. But its rare. I'm not saying you aren't pregnant. I'm saying it is too soon to know.