Rant! So much on my mind!

Hi all. I have had a WILD pregnancy and I'm only just hitting 6 weeks. I have been bleeding since what I am pretty sure was around implantation (9dpo), but I SWORE it was my period because I bled for 5 days filling a pad. Had no clue I was pregnant. Then what concerned me was when I spotted brown for the next 9 days. I randomly had this urge to test and IT WAS CLEARLY POSITIVE. I started freaking out and got in for an appt ASAP. I started spotting red too again and swore it was over. My hcg at 5 weeks 2 days was 163. No sac seen. My dr said expect a miscarriage. 2 days later my hcg more than doubled to 344!! I was so confused because of my (now) 3 WEEKS of bleeding. Two days after that, (yesterday) I went to the ER because I had red blood more and was like OK, this is it. They did another HCG and US and came back. My hcg didn't double in 2 days, but almost! (508) but obviously I am disheartened from it. Doctors said US showed a sac but no yolk sac/fetal pole which is expected this early! So my hope has slightly risen again. It is SO confusing! They said it is good news for now and I will retest my hcg on Wednesday, but I really don't know if this is an impending miscarriage or just my body being WACK. I literally have been bleeding wearing pads for 3 weeks, yet pregnancy seems to be progressing.