Hi Jenny and welcome to Share! Congrats on your son Oscar! So glad to read that he is healthy and growing right along. I don't have experience with the exact question asked, but I do know that there are many moms who had preemies and were able to carry the next baby either to term or for several more weeks. My first baby was a 32-weeker and his brother was a 34-weeker. They are 20 months apart. Your concerns are totally understandable. I was concerned about going through that same NICU experience again, but somehow I was able to put the worry aside knowing that each and every pregnancy is different. I had total faith in my good OB who kept his eye on me and our unborn son the first time. Know that you will (hopefully) be seen more frequently by the doctor and you'll discuss a plan. There's always the possibility of bedrest or reducing down to part-time, but you can discuss all of that with your OB.
Good luck and hear to listen,