Please help. I don't understand what is going on...?

Okay... Listen. I have no idea what is happening. I know you can't tell me if I am pregnant or not but I just need some advice please help. I'm 17, and on birthcontrol. I had about almost two and a half weeks ago. (for the first time) we did it without a condom and he didn't c u m it was only pre but I was on my period during that moment so I was on the placebo pills when I had ... My period is a 28 day thing. It is suppose to come next week at... Hmmmm I'm thinking the 8 or 9th? I know there is a chance i could be pregnant regardless but omfg if I am... There is just no way. The odds are so small for this!!! The reason I'm freaking is because yesterday I noticed my mucus was brown... Like blood brown. I didn't think anything of it. Today the same thing!!! I tried to see if clots were in it. I think there were not sure what it is at all! I don't know why this is going on!!! I have taken my pills correctly for the past days on time and perfect! I have been gy time to time. That makes my stomach hurt and cause acid reflux. I'm so scared, I dint have very sore (they tend to be constantly because I have rather large s) my back so fine. I have not gotten sick. I honestly don't know why my mucus is brown... I'm freaking out. Please I hope this isn't implantion or whatever. I've been having cramps today... After I ate. Oh it just can't be! I'm sorry if it seems stupid I just might have the worst luck ever...