This is a question I get daily. My response, "Mid September."
You can see them doing the math in their head. Yes, I'm only 5 months. Yes, I still have a LONG 4 months to go. Yes, I look pretty far along to only be 5 months. No, there aren't multiples in there. I then need to follow my response with, "But it's my third so I guess I'm just bigger. Plus I have really weak stomach muscles :)" That seems to placate them, although it's pretty clear they still think that I need to recalculate my due date, moving it up by about 3 months.
Let's see if I am in fact bigger...I've dug up a few pictures from roughly the same time. Here is a picture of me earlier this week at 22 1/2 weeks:
Here I am at 23 weeks with Cade, my first baby:
And here at 23 weeks with my second, Deacon:
LOL, I think that it's pretty safe to say that I AM BIGGER. Maybe it's because it's a girl (or is it??)...;)