14+4 belly feels so heavy

Meagan • Twin BOYS!! #2 & #3! Due May 25th 2016. Proud mom of an 8 year old boy.
I searched for similar Posts but didn't find any. Starting yesterday my lower abdomen feels so heavy like it's weighing me down. It's hard to walk or even move my legs without it feeling huge or in the way. I'm not very large, for carrying twins. It isn't pressure on my cervix or in my vagina, it's literally my lower belly above my pubic bone. Normal? Something to just look forward to for the rest of my pregnancy? Any similar stories?