I started to get a lot of discharge from about 25 weeks. At about your stage I was getting tons, I was having to wear pant liners and change them quite a lot. Its eased off now but I think it is quite common. I think as long as there's not a bad smell or it looks different to normal then I don't think it should be anything to worry about. If it is pink, brown or stringy then it could be the plug & then I would mention it to your MW.