Hey Carys - if you are above the coverline then its still a possibilty and the fact that you are still "feeling" a bit pg and the line is getting darker i would be going back for another BT - the hCG levels are supposed to double every 48 hrs so who knows - you might still be pg - or you might have had a twin pg and lost one - but do go back to the dr and get another bt to be sure... good luck!!!