Help!!!!!!!!!!

Hey everyone, so my story goes I was 10 days late for my period, peed on the stick came back negative, went to the doctors had a blood test negative, this was all last week. My doctor swears black n blue I’m pregnant I’m exhausted, eating lots, peeing heaps and my blood pressure is low. I started bleeding on Thursday last week lasted for 2 days then a bit of light spotting for a further 2 days. A regular period for me is 7 days heavy changing every few hours vomiting n the runs the cramps are ridiculous as well. I had nothing like this at all. So my question are could I have been to early to detect when I went to the doctors? Could the bleeding I experienced been implantation bleed? How long so I wait to see the doctor again? My blood pressure is still really low my boobs are sore I’m still very exhausted. Thanks everyone