When you first notice an increase in the size of your bust which is generally around 3-4 months, I strongly recommend you visit a professional bra fitter as they can ensure you choose the right bra for you. Yes you can make an appointment to come over to my studio for a fitting, we are in Auckland.
Depending on the development of your bust size you should be fitted again at approximately 7 months, however if you feel your bra is restrictive in any way and at any time throughout your pregnancy, you need to have your fitting checked straight away.
When making your purchase it is important to look for a maternity bra that provides excellent support and flexibility to allow for breast size fluctuation. An easy way to check this is to slide your hand into the upper cup section to assess if there is enough room for expansion.
Here at Breastmates we have a fabulous range of maternity bras which are suitable for pregnancy and breastfeeding. These are sexy lingerie under the Hot Milk brand.
View our website for more information about Hotmilk Lingerie and to order. We can send worldwide.
We also have a fitting instruction/sheet here which goes through some common problems: http://www.breastmates.co.nz/adv_bra_fitting.html
And a measuring guide and size conversion chart here: http://www.breastmates.co.nz/hotmilk_bra_sizing_guide.html