Maternity bras and clothing questions

[UntoldAngel]

Okay so i've had to look at maternity bras because my boobs have grown from 12DD to 12E in the last few weeks, and I think they are getting even bigger as the 12E's are starting to get too small... I've looked at maternity over just normal wireless because they feel more supportive
Because they are growing a fair bit, I have the following questions:
1 - when will they stop growing? (i'm 19weeks and assume they will be bigger again when my milk comes in)
2 - where can I buy cheaper bras to while they are growing? I've looked at Target, Big W etc but they rarely stock E and I don't want to be paying $50+ if they're only going to be worn for a couple of months

With maternity clothes, do they make the bum and thighs in them bigger as well??? I bought a pair of casual 3/4 pants in a 12 (my normal size) and they are massive in the bum and thighs and I feel like they are sagging I think I could have bought a 10 and fitted nicely. Has anyone else found this, or is it just me? I haven't lost any weight, I've been eating heaps and haven't been vomitting... just seems odd to me