I'm trying to use my wifi and its saying that I'm connected but it says no internet access on my computer but I can use the wifi on my cell phone? It was working fine last week but recently I have had no service...so confusing

Hi ringo20046 Welcome to D.A.L

We need to know a few things to help you.
Just how are you connecting to your wifi?
Is it via a dongle or a wireless connection from your router?
If its a dongle what make/model is it?
If its a router what make/model is it?
Could you also tell us what OS you are using

Jim23