Only happens in bathroom sink, not shower or kitchen sink. I turn on water, hot or cold and when I bend over to say, brush my teeth I get this mildew smell.
Ive tried bleach, and liquid plumber down that drain but it did not help. Any Ideas on how I can stop this odor?

The first thing I would look at is the stopper. Pull it and you will find a rod about 6" down in the drain. Shine a light down there and if you see a buildup of hair fish it out. If the stopper's tied down let me tell you how to free it up. Push down on the plumger so that the stopper pops up. Underneath the lavatory ahead of the clip you will see a knurled nut,(Leave the clip on)Now back the nut out until it's free but don't pull it all the way out. Now while you are pulling up on the stopper GENTLY pull the rod back until the stopper clears, stop! Now screw the nut back in place and just snug it up with a pair of pliers. When you clear the drain just drop the stopper back in. Some plumbers lock the stopper in when they install the fixture. I never have for it makes it impossible for the home owner to clean the drain. After you clean the hair pour a 1/2 gallon of bleach down the drain and let it set overnight without using it. Next morning flush it down with a pan full of boiling water. That should take care of your smelly problem. Hope this helps and thank you for rating my reply. Tom