Walgreens Positive Pregnancy Test

So last night I randomly took a pregnancy test. I had a Walgreens test and it came back a faint positive. I almost shitted myself because I have 3 beautiful kiddos, my youngest being 1 oldest being 10. We no longer want to have anymore kiddos so this is freaking me out. My period is due any day now and to complicate things even worse I’m on birth control soo wth!! I’ve had crazy headaches and nausea but I was contributing it to the heat. Today I went and bought a clear blue digital test and that came back negative. What do you guys think? I’ve also reas horrible reviews about Walgreens having false positives all the time.

Update: I started what looks like my period or I had an early miscarriage. Thank you all for your input.