The hummingbirds have been migrating back through for about a month. I'm in central Texas and have had a ruby throat pass through and have a male and female black-chin who reside in the area.
If this is your first year it could take quite a bit of time for them to find you. Are you in the city or out in the country? If they already have preselected areas out, this could be a reason why they don't always find you at first.
I remember my first year I put greggiis and feeders out. It took a couple of months before one showed up. Just keep a look out. Once you see one, they should show up more often.

Thanks for the insight. I am in the city, so yea I figured it might take me a little longer before I see any. I go out constantly throughout the day hoping to see one. I'll just keep waiting and hopefully they will find me soon! :) Thanks again!

Just be patient. It will take time and they will find you. I never even knew they existed in the city. You hardly see them. I did that my first year also. I kept going outside and checking to see if I had any! Don't give up!