Welcome
@jpg717 you might be one of those mythological "Great Aunt Tilly tap danced out of the OR!" people. That sounds phenomenal, what you've done, but feeling fantastic is no guarantee of being
healed, which is something your body decides the timeline for. All bodies take about a year to fully heal. There are many things you can do before that though!
Weight lifting adds stress to the stem, if you had uncemented. You want to give the bone plenty of time to ingrow to the lattice on the stem, and you only have one chance to get that right. On my second hip, at about 9 months, I participated in a group lift-and-carry-across-the-yard of a small marble statue, and had a ring of pain around the entire hip for over a year. OTOH, I was heave-ho-ing bags of clay cat litter and multiple full litter boxes around at just a couple of weeks with no ill effects.
Situps-- can you get down and up off the floor yet? I got stuck once and gave myself a lovely shoulder tendonitis using a reverse triceps dip thing to lift myself. Also, I am trying to remember how what felt when, with my anterior recoveries. Right this minute, I know how to isolate my abs doing very tight tiny curls (as in barre classes and maybe Pilates) with the abs only, no hip flexors involved. Maybe your OS would permit that.
As to pullups-- I had a real "this feels way too weird" antipathy to putting the hips into zero gravity situations. Even my first swim (in the ocean as had no pool) , many months after each hip, felt very very loosey-goosey and uncomfortable. Like my leg might fall off. I stuck with kayaking until the next summer, when all was well.
Definitely ask your OS. My "no activity limits" came at about 6 months for each hip. I still won't ever run/jog for exercise again, just to keep the wear and tear to a minimum, I've never skied, only surfed when I was 15, and have no plans to bungee jump or sky dive, so I'm good for life!