many times when you get these they are from the razor blade scraping the skin. either you just got a new razor, are using a cheap throw-away razor, or you are not using enough shaving cream/gel/foam.
Try to get a razor that is NOT mens (since they usually are sharper), a good quality ( i use quatro or something to that extent... has a bikini trimmer as well), and are using a moustrizing shave cream/gel/foam. if using foam (what i would suggest right now) use enough of it to cover all, its like a dollar a can. dont' be stingy.
also, use a moisturizer after shaving.
also forgot to add, do not use soap. at least for me, this does NOT do well enough to protect the skin. actually makes it worse.