Help. How to train my baby to bottle feed?

I'm currently 7 weeks pregnant and have an 8 month old baby. I'm exclusively breastfeeding and my baby doesn't like bottles.I have contractions while breastfeeding and my midwife said i need to train my baby to bottle feed because it is risky for my baby inside. I am practicing BLW to my baby now, and he can now sip through a sippy cup or straw, but he doesn't like the bottle.. I was worried that my baby will not get enough nutrients on milk :(