Looking on the internet deeply has found these results:

from last couple of days is the most popular phrase on the web.

since last couple of days 1158,000 results on the web	from last couple of days 1234,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
He's been gone the last couple of days. It never bothered him until these last couple of days. It's these new pills last couple of days. But you said some things the last couple of days. And the last couple of days, I haven't been doing that. You spent the last couple of days with us. Yes, within the last couple of days. Not that anyone knew, but his colleagues say that he's been acting secretive the last couple of days, ever since receiving a private communique from his wife.	But you said some things the last couple of days. You spent the last couple of days with us. He's been gone the last couple of days. And the alarm log from the last couple of days. And the last couple of days, I haven't been doing that. It's these new pills last couple of days. Yes, within the last couple of days. It never bothered him until these last couple of days.

since last couple of days

1158,000 results on the web

from last couple of days

1234,000 results on the web

More popular!

He's been gone the last couple of days.
It never bothered him until these last couple of days.
It's these new pills last couple of days.
But you said some things the last couple of days.
And the last couple of days, I haven't been doing that.
You spent the last couple of days with us.
Yes, within the last couple of days.
Not that anyone knew, but his colleagues say that he's been acting secretive the last couple of days, ever since receiving a private communique from his wife.