You don't roll into H for problems with your flight physical, it's only for people who are too injured or sick to continue training, or who fail an event during the first three weeks and need to re-take it with the next class (IST,Fast Cruise, RLP).
If something does pop on your flight physical you continue training while they work through the problem (getting followups, tracking down paperwork, etc.) so things are normal in that regard. Hopefully things will be wrapped up by the time you get to Candio phase so you're just waiting on NAMI to review your physical and grant you any waivers, if you need them.
However, that is not always the case. A number of people in my class are stuck in student pool because they couldn't get a necessary follow up appointment until after graduation, even though it is relatively routine and they should have no problems getting cleared. At least a couple need surgery for various issues.
If you are officially NPQ'd, you are given the opportunity to apply to other communities for redesignation. Several of my classmates are in student pool doing that now, as soon as you are picked up you have a private commissioning and then you get your orders to leave Newport for whatever follow on training you have,
TL;DR: There's a reason it's called the NAMI Whammy. The whole process is stressful even for people with relatively minor issues, and it sucks for those with more serious issues. And unless you are one of the very few lucky people who can get a physical with a flight surgeon before OCS, there's no way to really know what your process will be like until you get there.
in Jan.