I've never had a pram or stroller and my daughter is 2 years 3 months. She walks everywhere but I do sling her for a nap in the middle of the day (we are always out and about) on the days I don't work (husband does this the other days so she's used to it)
I'm towards the end of the first trimester, it is ok to still sling her? She's a ninth centile tiddler so not really heavy, although she's fairly tall.
I use SSCs and wrap conversion.
But this will be slinging for potentially 2 hours (I try to sit down for some of this) and can be knackering.