Sleep regression / sling use

[ChannelFiftySeven]

My baby will be 7 months old next week. Since last Sunday her sleep has been very disrupted.

She's never been brilliant at sleeping but we seemed to be slowly making progress. She has been sleeping in her cot by herself and has dropped her night time feed. She wakes a couple of times to be cuddled but that was it.

Now she is waking between 11 and 1, spends 2 hours awake and then will not sleep unless she's in my bed with me. Even then, she drops off to sleep and within 10-30 minutes wakes up crying.

Could it be a sleep regression (it's been the same for almost a week now)? Shouldn't she be coming out the other side of it now?

Also, we bought a new sling this week and I've used it every day for fairly long walks. She loves it, has some awake time and then naps in it. Could she be missing sleeping near me at night now I've reintroduced it in the day?

Thanks for any advice anyone has.