Ahhh yes, the kicking down low.....When I get that far along, it feels like my baby's foot just might come right out!!! LOL! Yes, it is perfectly normal.
At 30 weeks, it very well could be punches. I'm 34w2d and my lil princess punches me down low. Also, when she gets the hickups (funniest thing ever) it feels like little taps just above my pubic area. I know these are hickups because they are timed perfectly and usually lasts about as long as if you or I get the hickups.
I think it just depends on where the baby is positioned when he starts kicking. I'm only 22 weeks and I've felt my baby kicking/punching near my left side, then my right, and then sometimes I do feel her kick down lower. They will punch too, so she could be kicking her in the ribs and punching her somewhere else.