Positive OPK?

Jamie • TTC #2 for 8 years. Had an ectopic pregnancy 07.01.13
This is my first time using tests. It was taken a week ago and I am now 7 DPO. Don't expect this month to be different from the last 60, but you never know!
​Only thing odd for me is that I have craving vinegar the past week, have a full lower abdomen feeling and running a low grade fever (99). Any thoughts?