Yes, absolutely I’ve seen and made it happen multiple times. Sounds like a good thing in terms of if you’re getting that into it and feeling that comfortable with them then they are probably doing things well.
It’s definitely something the two of you need to talk about as you’ll respond differently when in subspace, be less able to give coherent, considered responses and use things like safewords, so they’ll want to talk it through and make sure they are being extra careful looking after you if you’re learning to slip into that place.
A little warning though, as lovely an experience as subspace is, don’t chase it too hard. When it happens that’s lovely, but don’t make it the sole aim of your play together – it’s a common mistake I see some subs do, ‘chasing’ subspace, and if you’re not careful it takes the shine off everything else you do, which would be a shame.
I hope that helps,