haha believe me; i'm a expert pube shaver. Once a week, every week=) The itching was caused by razor burn (im sure there were some red bumps also). You can prevent razor burn by:
1. use lots of shaving gel (gel, not cream)
2. wet the area with warm water before hand
3. press lightly with your razor; too much pressure is was leads to cuts and bumps. Hold the razor steady, but dont press hard.
4. shave with the grain. Go over each area a few times with short, light strokes shaving with the grain.
5. Moisturize the area with body cream or lotion both directly after you shave, and every time you get out of the shower. Showers dry your skin out a lot (mostly due to the soap) so you gotta keep the area moisturized.
Do these, and youll be itch/bump free and looking sexy