6 weeks, yolk sac gone ?

so i had my first ultrasound tuesday, i measured 5 weeks 6 days. we saw the yolk sac but no fetal pole. i had some spotting but there was nothing concerning on the ultrasound. thursday night i started bleeding more heavily, i went in for another ultrasound friday (yesterday) i’m now measuring 6 weeks 3 days so it did grow completely fine. he said he didn’t see any signs of detachment/separation of the pregnancy. the only thing is we couldn’t find the yolk sac. we did see the start of the fetal pole and i even got to see the flicker of the start of the heartbeat. i go back next friday for another ultrasound. he said it could just be the position and angle of the ultrasound or just that his machine is really old. but i’m a worrier and i literally cannot find any information on a yolk sac disappearing when i’m researching and i just know i’m going to drive myself crazy until my next ultrasound. has anybody gone through anything similar ?

Top is 6 weeks 3 days

bottom is 5 weeks 6 days

also this is another ultrasound i got at 5 weeks 6 days at different clinic