Not period for a year

hi guys i have a friend who was pregnant last year but she had and abortion because the baby wouldn’t survives(she had a vaccine and she didn’t know that she was pregnant😢she was 4 weeks pregnant at that time)since then she doesn't have her period and she wanna try for a baby but without a period is impossible,she’s so devastated it because she wants a baby,she’s irregular but she used to have her period a least every 3 months,she doesn’t know what to do,her doctor told her that everything is gonna be back to normal but nothing happens