I read on a website (unsure of how true it is) that 6% of negative HPTs turn out to be positive blood tests? Are blood tests at the doctors more reliable than urine tests? I have done two HPTs one when my period was due and one on Friday which was a week and 3 days after my period was due, both negative (also both 'early detection').. I don't think my doctor (who is only usually available with 2 weeks notice!) would give me a blood test after 2 negative HPTs but I only had slight brown spotting in place of my period and now this past week I have been feeling nauseous constantly and thinking of food makes me want to throw up, so was looking at going private for a blood test just so I can have piece of mind?