Is it possible I could be pregnant? My period came 9 days before it was supposed to, very light, its been about 3 weeks and I'm still cramping,

Yes, but probably no. When you say "period", i assume you simply mean bleeding. Bleeding can happen anytime. A true period only occurs 14 days after ovulation. You had a "light" bleed, which is common with implantation of a fertilized embryo. Get a pregnancy test and, in the meantime, start a prenatal vitamin with folic acid. The odds are probably very low, but if so, now's the time to ensure it's a healthy baby.