Could it still be implantation?

So I'm 5w & 3d. About a week or 2 ago I notice a small amount of brown spotting. After reading up on it I knew it was implanting. But yesterday a few hours after having sex I used the bathroom & noticed a small amount of red discharge, I understand if it's red it can be a miscarriage but it wasn't alot, a very skinny line but it was only one time so I tried to put it out of my mind. Today it was a milky stringy clear/whitish/light brown spotting about the size of 2 quarters but not clumply just gooey. I'm getting a little concerned now. I have had one miscarriage about 2 yrs ago. Should I be worried? I don't go to my first appmnt for another 3 weeks, pls tell me this is common maybe??