I'd say it's probably fine in moderation since it's just ice cream and chocolate, but the thing with pregnancy is that soft serve machines aren't always kept as clean as they should be, so there's a small food safety risk there. If you're craving it badly, maybe stick to the packaged ice cream from their fridge instead, or just bring it up with your gynae or PD at your next visit to put your mind at ease since everyone's comfort level is different during pregnancy.
In moderation is fine.