Ultrasound at 5 weeks 1 day and no sac

Hi guys, my doctor sent me for early ultrasound today because I have history of ectopic. I’m 5 weeks and 1 day and my levels where high- hcg 3600 and progesterone 41. So technically I believe you should at least see a gestational sac on vaginal ultrasound. But we just saw a thickened lining. No sac. It didn’t appear my tube had anything in it either. So far, no pain or bleeding like i had with the previous ectopic. Has anyone had this happen? And if so, what where your outcomes. I’ll have more labs on Monday and then another ultrasound next week but I’m trying to mentally prepare myself.