possibly pregnant?

had a twin miscarriage in july so irregular period and hormone levels but my hgc was 0. then i had bleeding on the 19th of nov my period was due pn the 21st but i felt pregnant. so after that bleeding started i figured not pregnant.waited til the bleeding stopped and took a hpt and 4 others all negative. then on the 25th i got really nauseus and had one last digital BFP!! so excited go for an ultra sound and no gestational sac. my blood work came back less than 5 hcg.no spotting after the bfp and they saw a cyst on my ovaries and my endometrine is 16mm thick. am i pregnant or is it the cyst bexause o still have nausea and all my hpt are negative not even the digital is reading pregnant anymore 😣 going for more test next tuesday.. any advice?