Did you efile it or print and mail it yourself? If you chose to mail it, TurboTax doesn't mail it for you.

Here is where to confirm an efiled return: 

I Efile and it said it was accepted on the 27th of March

Make sure you are entering everything correctly to access it on the IRS web site: https://www.irs.gov/refunds

Here is an IRS Q&A about the process: https://www.irs.gov/refunds/tax-season-refund-frequently-asked-questions