WTF?! LH Surge day before expected period

So my sides were really cramping (more than normal) and I figured it was my period as its supposed to come in the next 2-4 days... but normally my period cramps are not on my sides ovary area so I did OPK test HOLY SUPER POSITIVE LH surge?! This is NOT supposed to happen the week of expected period right?! Did a pregnancy test right away after and it came back Negative... HELP?! Has this happened to you?!

Below was supposed “surge”?! 12/31 ....