missed my period by 11 days could I be pregnant??

hi I did a pregnancy test 2weeks and 1 day ago and it came positive with a faint line ( always do test as trying) I'm now 11 days late on my period I've done a test today and it's come up negative I don't understand how I got a faint line like 2 weeks ago but now a negative test? I had a miscarriage in December been trying since! I do keep getting a few symptoms ....... Can anyone help me please?