I just got an HSA starting in February. Can I contribute money for last year (before April 15)? I had an eligible high deductible plan all last year.

I did not have an HSA until February of 2018.  But now that I have this new account, can I deposit money for the 2017 tax year and get the deduction on my 2017 taxes?   I had a high deductible insurance plan all last year, but no HSA.