Ah, common concern talaga ito! Honestly, a few of us continued breastfeeding through the second pregnancy, it's generally okay, but nipples can get super tender, so I stopped around 7-8 months kasi ang sakit na talaga para sa akin. Best to check with your OB though, especially kung may history ka ng preterm labor or complications, kasi bawat pregnancy is different. How's your firstborn handling it naman, and do you plan to eventually tandem feed?