Pink Discharge: What does it mean?

So I've been noticing recently in the last three days that I've beginning to get pink discharge. I've had unprotected sex whilst on the combined pill with a new partner and he's clean and so am I. We've both had chlamydia in the past but both had the all clear once it was treated. There's also a slight smell to it as well but I can't relate it to anything. What could it be?