Hi! I sell nursing bras in my store, so I feel I have some experience here. My recommendation to my clients is to start with something like a Bravado, that has give for the transition from maternity to nursing. These bras even have enough give for engorgement, if you have that. Once your milk is in, you can get a good, supportive bra. Now, since you don't want to spend $ and Bravados are $35, I would try the nursing tanks at Target, or a softcup. [I have never tried the Target tanks, have heard they aren't very supportive, but they should work in the interim.] Definitely no underwire until someone can fit you after your milk is in. Don't try to predict your size after your milk comes in. It doesn't work. There are rules of thumb, but they fail as much as work. If you have a bra store or a nursing store in town, I would highly recommend going there to be fit and find a bra that is right for you.
Since Target, Motherhood, etc don't have someone who can fit you, here is a way to find out your size. In my store, we use this as a starting point, but don't take this size as gospel. To figure out your current size, take 2 measurements. Make sure the measuring tape is level for both measurements.
1. Measure the area above your breasts and under your armpits.
2. Measure the area around your breasts.
3. Round up #1 to the nearest even number. This is your band size.
4. Subtract #1 from #2. The difference tells you your cup size:
1=A
2=B
3=C
4=D
5=E/DD
6=F
7=G
etc.
So, for example, I measure 35 1/2 above the breasts, and 44 around my breasts. My band size is 36, and my cup size is an H. Many factors affect how precise this measurement is, like how tight you hold the measuring tape, if you have a thick shirt on when measuring, if you have a supportive bra on, etc and so on. So use this as a starting point. Keep in mind, too, that a smaller band size with a larger cup size is more supportive then the other way around. Many women are embarassed by their large cup size and try to compensate for it with a larger band size instead. But your bra will be more supportive if you go in the other direction.
Good luck and sorry for the novel. I have a tendency to go on and on about things I think I know something about. Hope it helps!
