Re: how soon did you wear maternity clothes?
The first time I was wearing elastic waists around 2-3 months...this time, I broke out the maternity jeans the day I found out! Seriously, I think I just quit bothering to suck it in at that point but I did start showing a lot earlier. I think part of it depends on how long you had between the two pregnancies...I had never really gotten my shape back so it was easy to stretch out again.
If you don't want to go into maternity clothes, have you seen the "belly bands" that are just like a belt that goes around the waist of your pants to hold them shut without fastening them? It looks like you're just wearing layered shirts...very cute.