Solid smiley on Hpt day?

I'm due AF on Tuesday. Tested today and BFN. However, I took an ovulation test at same time and that is showing a solid smiley? 
​What do you guys think? 
​Can you be fertile twice in one month? I only came off Bc in February so dunno if this is why I'm getting odd results?  CM is very wet and slippery. I don't feel pregnant nor do I feel like I'm ovulating - I'm usually pretty in tune with my body. Any advice welcomed pleased!