Pink fluid leaking from nose!? HELP!?

My bf has had the flu for the past week or so, is just getting over it. Went to the dr today and they said he was getting over it fine and his lungs clear, etc. He hasn't been too congested nasal-wise; but earlier he felt a trickle down the left nostril and thought a nosebleed maybe yet when he wiped it with a tissue it was like pinky coloured water!? Bit worried