Pos OPK?

Brittany • Chloe Elizabeth 7-30-13. Sophia Grace 10-15-15. Baby #3 09-20-16
I took an ovulation test yesterday morning, no it was not FMU, and it came back positive, took a pregnancy test and it of course came back negative. I checked my cervix yesterday and this morning and it is definitely high, closed very tightly, and soft like lips. I did have spotting last night, but it was only for a split second and after that it stopped and it was only when I wiped, and very pale pink, hardly even noticeable. Is there a chance that the OPK picked up the pregnancy hormone before the HPT could since my levels aren't high enough yet? I do have mild cramps, aching boobs (like painful to the touch) gassy, elevated body temps, frequent urination, cravings, and aversions to smell, my boyfriend is now calling me 'Brittany the Nose' lol and not to mention, I can't even eat cheesecake anymore, and to know me is to know that I LOVE cheesecake! I don't know if this helps with advice or anything, but one app says that I would be 4 DPO today.....I just don't want to get my hopes up but I can't help but feel it ya know!