Feeling HUGE already

Sara • Expecting twins In September 2016. Mommy to a fantastic 2.5 year old and married to a wonderfully supportive man.
I know it's crazy and probably all in my head (or just bloat) but at 4 weeks 3 days I feel like my tummy is huge!  It's my second baby so I know I will probably get bigger faster but daaaang!  Anyone else feeling the same?!