Advice please ladies xx

Hey lovely ladies x 
So in a bit of a dilemma!
I know how annoying pregnancy posts can be, but I'm posting because I'm at desperate measures and in need of some sort of help. I'm currently on the implanon, which is the most effective form of contraception, but 1 in 100 have the chance of becoming pregnant which is fairly high.
Of late, I haven't been spotting as I regularly do, instead the normal everyday discharge. 
For roughly the past week, my nipples in particular are extremely sore, irritable and sensitive, which could and most likely does suggest change within the body. 
I have adjusted to the hormonal change of the implanon,  that I am sure as my emotional state has finally reached its equilibrium and isn't as crazily imbalanced as it used to be. But for the past week, it's been absolutely horrible! I have been 50x hornier, 50x angrier, 50x happier, it's just been heightened! 
So with all of this, I took a pregnancy test which tested to be negative! 
But these symptoms persist to cloud me and confuse and I was wondering what you ladies thought should be my next move?
Thank you so much for taking the time to read this x