Any ideas?

Guinevere
Okay so I'm going to my gyno soon anyway, but maybe some of you have some ideas.
So my body has started acting like its pregnant for the past couple of weeks, but so far I had one test that was so faint it was almost invisible, and the second was a negative.  Now I took the first was really early too if that means anything. I'm coming up on what should be my period, and yet nothing. I have a lot of discharge, but no signs or spotting or anything. Also these "symptoms" (like sore breasts, some weight gain, lower back aches, indigestion, food aversions, and mild nausea late at night) are all still present. Some of them are becoming milder, but they all sort of flux. In short, none of them are going away. 
I should also add that this is the third month I've been on the pill. 
Has anyone been through something like this? Anyone have any ideas? Should I test again?