Lots of women BF while being PG,and tandum feed once the new bub comes along, you have to look after yourself, plenty of rest (not so easy) nutition, and keep up the water intake. your body will have a lot of demands put on it . Some women have nipple tenderness from the hormone changes. I remember hearing that later in the PG your milk will turn into colostrum ready for the new bub,and this is where some older babies may self wean, others stick with it and you may decide to tandum feed. The ABA is a great place to find out more info. HTH
congrats. on your pg.