Faint line

So, for the last few days my breast have been burning, tender and swollen; I’ve had bad headaches and sleeping a-lot more too. Random cramp spurts while driving as well... my boyfriend thinks I’m pregnant so I went out yesterday and got one of the $1 DG tests. When I used it nothing came up, but I had to hide it under the sink so he wouldn’t see it. I went to throw it away this morning and saw a faint line. What do you guys think??? I’m also and have been on the Nexoplanon implant for 3 years now but runs out in August. Can I get pregnant off of that??