Do you keep track of cervical changes during the month? Meaning, are you super duper familiar with your "lady sphincter"?? Because the fact that this is your third baby means that the OUTTER ring of your cervix is nice and stretchy and loose as compared to a lady who has had less "activity" down there.
I'm VERY squishy and soft and can fit WAY more than just the pad of my finger in there...like, I can kind of swirl my finger around...I've got a LOT of room for a finger, if ykwim! (sorry if TMI)
I am almost 19 weeks...and here's the thing about me....with all of my babies so far, by 30 weeks, I've got an extremely soft, barely there cervical neck, am not really dilated at all....but have a baby IN my vagina....like, as in, midwife making weird faces and being like "oh my god, you weren't kidding" - when she goes to "check me out" and gets about 1.5 inches into my vagina with a finger before she is hitting soliidddd baby head. I carry my babies like that for the last two months of pregnancy. IN my vagina. Must be why I have had a 97 minute birth and a 110 minute birth, you know?
So, I don't know if I just start "relaxing" down there a bit early, or what....but you may also be that way with this baby, you know?
Listen, if you are concerned, you should always talk to your care provider....I always say, the number one reason you should ever call your provider, is if you think you should call your provider.
Worst case scenario; extreme bed rest, a couple of different natural and/or synthetic remedies and proper monitoring...and your baby has got a much better shot than you might imagine, if the only problem is a somehow incompetent cervix. Don't stress about keeping your baby in...if they've got good enough lead time, they have a good shot at keeping your baby in. Your body dilating your cervix to try and get your baby out...not so good, but still, they can help you. But your cervix just kind of falling open....they can do a lot for that if they have enough time.
But baby, listen, your cervix is not just falling open. You're on your third baby...the chances of your cervix carrying two babies just fine and then just kind of crapping out on you for the third one....are just so so so small. Like, SERIOUSLY, I'd bet the farm that's not happening.
So, just to recap: I'm 18w5d with my third baby and my cervix is soft as is could possibly, POSSIBLY be, with an outter ring that is very loose that I can really swirl my entire finger tip around in and I can stick my finger very DEEP inside of this squishy, loose cervix....but at the top of that, we've BOTH still got a tight as fort knox inner cervical ring (not the proper terminology!), I promise! I also get cramping after sex and sometimes just randomly.
If it's concerning to you, I'd call my provider...always take heed at your own feeling of concern...but I would try not to worry too much, because I think it's really normal for a third+ baby.