Advice - period late

Hi ladies so I am late on my period by 7 days now. I have had the copper coil for about 2-3 years now and I’ve always been late by two days according to this app. However I have never been this late on my period.

I have checked that my coil is still in place and it is, i have also taken 2 pregnancy tests and they have both come back negative?

Any one have any ideas to why I could be so late on my period this month?

Thanks in advance