I shaved with a razor that had some rust on it I didn't notice the rust at the time... now I have what looks like a rash wit itchy red bumps that look like pimples... never had this prob before when I shaved down there its only on the top part of my vagina and on the outsude of my lips.. its very sore and itchy.. what could it be?

You abraded your skin when you shaved with a probably dull, rusty razor. Wash that area with a gentle soap and put an aloe gel or lotion on it (NO alcohol!). If it hasn't improved in three days after regular treatment, go to the doctor for a check.

Thanks so much I will def try that

The razor also probably did not cut the hairs clean, so you might end up with some ingrown hairs (pimply bumps).