Negative urine

Hi. Ive had a few negative home tests. Went to the doctors as im 7 days late and was a little concerned as ive had a little blood each time ive had intercourse in the last week. She did a urine test there and it was also negative. Before she investigates the bleeding from intercourse further shes sent me for a pregnancy blood test. My question is there any point of thos when alltests have been negative? Has anyone had negative tests but positive bloods? TIA