Also, unless your total Capital Loss Carryover is $3000, don't only enter $3000.  Your entire carryover should be entered in the program, and the program will determine how much is able to be used (and it will automatically carry over the rest to next year).

Just noticed it says Deluxe on your post.  You need Premier or higher to enter a Capital Loss Carryover.  If you used Deluxe then where did you enter it?

A capital loss carryover does not get entered directly on form 1040. A long term capital loss carryover shows on line 14 of Schedule D.  A short term capital loss carryover shows on line 6 of Schedule D. 

The carryover loss(es) will fist be combined, on Schedule D, with any other capital gains and/or losses for 2017 and the net gain or loss goes to line 13 of form 1040. 

Do you have any amount on line 13?  Could your gains be more than the loss?  Capital gains can also come from interest, dividends and K-1 forms.