I'm in that mindset too, although a long way off TTC3 if that ever happened. We are still both in the middle on this, but today was the first day that DH conceded that maybe, just maybe, 2 is enough. I've been back and forth on it, DH used to think 4 was a good number...
What has prompted this right now is actually a D&V virus. DH has it, as does DS1. Fortunately DS2 and I are fine. I am tired, looking after all 3, I keep being vomited on (by DS1, DH is polite enough to use a bucket), DH feels useless, I've done a ridiculous amount of laundry. I know this will be over soon, it's one virus, but kids pick things up, and hard things happen beyond bugs. Do we want to do that 3x? Not entirely sure on that one.
The other attraction is how much easier it would be, practically. When I think of stopping at 2 there is a little bit of relief inside, knowing I won't have to be pregnant again, and knowing I won't have to heal again (the labour bit has always been the easiest so far!). I realised that if I'm feeling relief at the thought of stopping, it's probably a good idea to stop!
I'm not 100% decided but I can now see that I would be fine stopping at 2. Analyse how you feel and react to the idea of a 3rd, genuinely, the idea of not doing it one more time. Like if you feel like it could be all sorts of tricky and yet, you still want to, that's probably an indication that you really want a 3rd.