Hi, I'm 22 years old girl at recent I have slightly pain at left lower abdomen with yellow discharge of vagina about the discharge I give some medicine(14 days meranidazole with doxycyclin) after this medicine my discharge become very slight and bright yellow(WATERY YELLOW) but I'm worring abou my lower abdomen pain...
Thanks very kind of you to help me

I don't know where you are in the world, but your next step is to tell your doctor that you still have pain, and discharge. You probably need an ultrasound and a culture of the discharge. Both drugs you took are antiBACTERIAL. You could have a different kind of infection.
Did you have any kind of physical exam?
See a woman doctor if you didn't, and aren't happy.