Help? BFP OR CYSTS CAUSING FALSE?

I got these tests cause they are the only ones that they had in stock.. Long story short was up at hospital last Saturday with pretty bad cramps they took a urine sample to do a pregnancy test came out negative, dr ruled out ectopic due for ultrasound on pelvic area, my GP said to test as he thought I pulled a muscle (he's a bit of a quack). But followed Drs orders and got this? Taken with in 3-5 minutes.. Help?! Can cysts cause false positives? Tested negative exactly 7 days ago.. I'm still lightly cramping and have nipples that are soooo sore?!