Sabar dulu ya, keputihan kuning sikit2 tu boleh jadi normal especially pregnant, tapi since you've dah jumpa doctor dan ambik ubat yang dia suggest, best you follow up with him/her lagi untuk confirm the results or if it persists, jangan worry sendiri about GBS or c-section risks lagi because your doctor yang terbaik tengok situation you fully. A few of my mum friends had similar concerns and the doc just monitor from time to time, so ask yours if you need regular checkups je or wait for delivery nanti. The main thing is you're already being proactive going for the sample, so trust the process lah and raise all your worries with your doctor next visit, they'll explain which risks apply to YOUR situation specifically.