I have not had a bowel movement for 7 days. Should i be concerned

bowel movemets

No. I sometimes don’t have a BM for 10-14 days. 
If you are eating zero carb then you have very little waste to move through your system. 
Get out of that old mindset that I have to take a dump everyday. That world is over. 
If you just aren’t experiencing an urge to go then there’s just nothing there. 
If on the other hand you are feeling like you have to go but you’re stopped up or you are trying to push gravel then you are constipated. 
In that case you could start taking a magnesium citrate supplement. That will soften your stool. You could take a laxative but i hate the chemical stuff. I have an herbal tea I keep on hand called Smooth Move. It work really well. 
I felt with true constipation for about a year on carnivore. I think it was due to the fact that I don’t have a gallbladder but it eventually worked itself out as my body adjusted. 

In the very beginning that happened to me. I wasn't concerned as I was feeling fine. 

I'm averaging 6-7 days as well. I eat a lot of fat and maybe at times my ratio is slightly higher than the norm. I get loos when I do go.

If I lower my fat content and I get a little constipated. 

Scott

It changes once you're fully fat adapted. I am dropping prime dookie, smooth as a nuclear submarine, don't even have time to see what's what on my phone.