Why was my blood test inconclusive?

On Saturday I took a HPT and it came out positive. The same day I went to the doctor and the urine test there came out negative at first then after a while a very faint line came out. So doctor sent me for a blood test on Monday and on Tuesday afternoon the doctor phoned me and told me he doesn't know if I am pregnant or not as the blood test was inconclusive. He said I should go for another blood test after 48 hours but i am just worried I will get another inconclusive test. Has anyone ever had a similar experience? what was the outcome? p.s been very fatigued, sore , heightened smell and nauseous. Also I stopped the pill the first week of June and straight afterwards got a period that was earlier than it should be but I haven't had a period since, could this also have an affect?