Hay nako mama, I totally understand your worry especially after what you've been through, those fears don't just go away. Brown discharge in second trimester can be normal sometimes, pero dahil sa history mo and kung persistent siya, kailangan mo talaga mag-check with your OB para ma-ease ang mind mo, okay? One of my mum friends had the same scare and when she got checked, everything was fine, pero ang importante talaga is you get that peace of mind from your doctor directly, hindi lang from online answers. Sending you lots of love, you're doing great by being cautious.
Jovilyn