Right, I'm going to sound so stupid but I can't find anything on Google.

I've been on the implant since April 9th 2017 I haven't had a period since and I haven't had any period pains etc, because of this I do a test every 2/3 months to make sure etc ( all come back negative) the last 3 weeks I've had signs of early pregnancy ( vomiting, sore breasts etc) I'm not unwell, haven't changed my diet or added anything to it that would make me unwell. I took a test and it come back negative but I was just wondering if you could get pregnant and the test come back? negative?