My then-girlfriend (now fiance) was a class below me in medical school. We were both busy at the time; her with exams and me with Step studying. I gave up a lot of vices that, when they add up, waste a lot of time (deactivated FB, stopped playing video games, etc.) I would study with her, which was our "quality time." My alone time was spent in the gym or asleep. One night a week though we promised to go on a "date" for a few hours and not talk about medicine or school. Believe me when I say it was rough, but she made it better. She cooked for me, helped around the house, and stayed on top of me with my study schedule. And I did the same exact thing a year later when she was studying for boards (luckily I had easier rotations at the end.)
One guy I was close friends with had a girlfriend of 6 years outside of medicine. She worked 9-5, M-F; the normal job. She thought he was cheating or at least lying about where he was--who in the right mind can studying 8-12 hours a day, every day, for almost 3 months, all-the-while supporting a 500-mg-a-day caffeine addiction? She sat down with us at 8 am on a Saturday in the library. Got bored, left by 9:30 am. She came back at 6 pm, only to discover we were still in the same spot, studying as hard as we were when we started. Before she saw this, it was constant fighting. After? She was sweet to him until he finished the exam. They made it work. She helped around the house, did the general chores, made sure he was eating right, etc. It's a big sacrifice that won't go away for a while. It's a big give-and-take. If your S/O can understand the lack of attention and alone time, then y'all will make it work. If your S/O is needy, then it won't work. Because this isn't as temporary as just one test. It's another 2 years of medical school rotations + 3-7 years of residency + 1-3 years of fellowship.