Dr. doc gave me metronidazole to cure vag bv, just completed 5 days 250mg course still no change in yellow-green discharge with no smell.19 week preg?

Another infection?: BV symptoms should have improved by now, and it is unusual to have BV without odor. (In fact, odor is usually the main symtpom of BV, not discharge.) And yellow color suggests the possibility of other kinds of infection, including STDs. So my guess is you didn't have BV, or had BV plus something else. Return to your doctor for further evaluation. STD check may be necessary. Good luck!