I have had 3 positive urine test for pregnancy, blood draw was negative, i am 43, what could of caused this.

Several things: I don't know your age or medical status. But, the most common are a mistake in testing, use of medications that contain what is being tested, and production of hcg. False positives may also appear on tests used past their expiration date. If you have taken HCG injections as part of infertility treatment, you can be false positive too. Some tumors and IgA deficiency can also cause false positives.