Email problems

I just had a friend email me something thru my gmail account. I was trying to check the email on my phone and nothing was showing up. I kept telling him, "Hey, I didn't get your email." I kept hitting refresh on my email and made sure the notification/receive email thing was switched to on. So after like 4 attempts to see this email, I forgot about. I checked my email on my computer and it was there. Four times! So, then I went to my phone to see if the email arrived on my phone and it still wasn't there. The email was sent like 20 minutes ago and the email is not appearing on my phone despite hitting refresh and even restarting the phone. Anybody had any problems like this happen to them?