This happens to me to when the baby is moving sometimes it's so jerky and rhythmic that I have thought it to be seizures too. Such an odd feeling. The hiccups I feel are slower and softer. This must be normal since seems pretty common and I've never heard of fetal seizures.
It's def different from hiccups- they usually last for a couple of minutes and have a rhythm to them. What I'm experiencing is more like twitching really fast for a couple of seconds, such a strange feeling! Maybe it is the baby.. I just didn't think he/she would be able to make sudden jerky movements like that, that's why I thought it might be my uterus. Who knows, I'm not too worried about it. I will get to meet him/her next Thursday, yay!!
I asked a friend of mine the same question and she said it freaked her out so much that she asked her OB about it when she was pregnant with her daughter. Her ob told her that its most likely the baby rolling around and between fluid and their knees etc rolling across the inside of our bellies it feels sorta like a spasm type thing. its a realllyyyy odd feeling lol DH felt it the other night while going to bed and he was like omg what was that! lol
Maybe it's hiccups? I have been feeling little sessions of baby hiccups these past few weeks.