Cyst / empty second sac and bleeding at 12 weeks

[SkyBlue20]

I had my 12 week scan this week and the sonographer said all was looking perfect and nothing to worry about but she noted a cyst or what could be an empty second sac next to the sac the baby is in. Said she was going to note it on my report so it could be checked at the 20 week scan but nothing to be concerned about. It wasn’t noted at a private scan I had at 8 weeks or at 11 weeks (due to bleeding) - but at the latter they did say they couldn’t see my ovaries, so I don’t know if that’s why (I also realise that private ones aren’t as thorough or medical as the NHS ones).

For the last couple of weeks I’ve had very slight brown discharge and the day before my scan, had a couple of heavier bleeds (on wiping only), still brown. That trailed off over the last few days and all was back to normal but then tonight I’ve had a heavier (but still not crazy heavy, only on wiping) bleed that’s like a dark red/brown mix.

When I asked the sonographer if the cyst/empty sac could be causing the bleeding, she didn’t really answer and I just wondered if anyone has any experience of anything similar at all? I’m going to call the EPU in the morning if I still have blood but figured I’d ask. I’m just so confused and so constantly anxious as I have had a MMC in the past.

Thank you!

I've no experience but if the empty sac had used to contain a twin, that could cause bleeding? But would that have been seen at your earlier scans?

I did wonder that but the one thing the sonographer did say was that it would likely just be reabsorbed. Seems quite coincidental though that I’d have it and have quite consistent bleeding? 🤷🏻‍♀️

Just an update in case anyone finds this when looking for a similar problem in the future. I called EPU and they got me in for an internal check - all looked ok and they booked me in for a scan three days later. Baby was absolutely fine and there was no sign of the second sac/cyst anymore. The day after the scan, the bleeding stopped and it’s now been just short of a week and I haven’t had any more since.
Sonographer said it could have been the sac/cyst or it could be that my placenta is quite low and next to my cervix so every time it grows and lodges in further, it bleeds and some trickles of blood escape out of the cervix. She was not concerned at all. I’m inclined to think it was the sac/cyst with it no longer being there and the bleeding stopping.
Will see how I go but hopefully that’s the end of it now 🤞🏼