No emails on phone for three days BUT they are on my laptop
Assuming you actually mean Email and not messaging, Email is considered data. So you will either have to have cellular data enabled or be connected to the Internet on WiFi.
The second thing to check is to make sure the Email account is synchronizing. Go into your phone settings menu and select “Accounts.” Select your Email account to see the last time it synchronized or to turn synchronization on if it is toggled off. If your Email account is not there, then you need to add your Email account.
In addition to the good answer from @marshallh it is possible your notebook is configured for POP access instead of IMAP. POP can be configured to delete messages from the mail server when they are fetched which will, in turn, delete them from a phone configured for IMAP. If this is the case, reconfigure the laptop to use IMAP and the email on the phone will be synchronized with the email on the notebook.