bloating, constipation, headaches

Hi all, I'm new to this so is a bit strange.

 Me and my partner have had unprotected sex since we have been together, however this isn't a problem (so Ithought) because I have the implant and so far had it for 2 years .. I've never had a problem before but recently I haven't come on my period for two months, which I know is a side effect of the implant but ive always been regular with it anywayHoyt I've been experiencing bloating, constipation, headaches, naesugas sand and shortness of breathe, all of which I'm told are signs ofpregnancy.

I did a wilkos own pregnancy test and it showed to be negative so why am I experiencing all these problems? Would it be best to ry another one? 

 I've talked to my doctor and hebelieves there is no way of me being pregnant because of the implant however I've heard of people whohave been pregnant while having it.

Im very confused and wondering if anyone could help? I'm alsohaving my implant taken out on Monday!! Very undecided whether I wasn't that done now or not......  I don't have another signs like darker areoles or tender breasts however have had pains as though I was about to come on my period but I haven't and that was two days ago!! 

Please help, thank you. Me x