Hey mama! Congrats sa 22 weeks! Honestly, hindi ka nag-iisa, maraming mums struggle with the consistent timing kasi halos impossible talaga laging exact same oras, lalo na pag night shift or irregular sleep. The good news is, prenatal vitamins are pretty forgiving, a couple of hours difference here and there won't really tank your absorption, especially if you're getting most doses in on time like you are.
What does matter more is taking them regularly overall at spacing out the iron and calcium-based ones (kung yun ang nire-prescribe ng OB mo), kasi sila talaga ang mahirap i-absorb together. As long as you're consistent most of the time like you mentioned, you're doing great, perfectionist timing isn't really necessary. But since it's your OB's specific prescription, worth checking in with her kung okay lang yung flexibility mo, just to ease your mind!