Itchy nipples at 12 weeks?!?!?

I'm 12 weeks as of today and my left nipple is so itchy!!! Is this normal? I also felt a sharp cramp earier but have had no bleeding or anything out of the ordinary since then. Should my lower abdomen start feeling firm now? I have so many questions. Oh and is quickening felt at 12 weeks because I think I've been feeling it.