Table 2.
First dose of COVID-19 vaccine and it is the effect on the menstrual cycle (N = 2338)
| Variable | N | % |
| Which vaccine did you get for your first dose | ||
| AstraZeneca | 627 | 26.8 |
| Pfizer | 1694 | 72.5 |
| Moderna | 17 | 0.7 |
|
On which day of your menstrual cycle did you get your first dose (where day 1 is the first day of your period) | ||
| 1–7 | 497 | 21.3 |
| 8–14 | 482 | 20.6 |
| 15–21 | 656 | 28.1 |
| After 21 | 703 | 30.1 |
| Q1. After receiving the first dose, your next period was | ||
| Lighter than usual | 574 | 24.6 |
| Heavier than usual | 338 | 14.5 |
| The same as usual | 1426 | 61.0 |
| Q2. After receiving the first dose, your next period was | ||
| Earlier than usual | 393 | 16.8 |
| On-time | 1297 | 55.5 |
| Later than usual | 648 | 27.7 |
| Q3. After receiving the first dose, the cramps you experienced in your next period was | ||
| Worse than usual | 619 | 26.5 |
| Less bad than usual | 182 | 7.8 |
| The same as usual | 1537 | 65.7 |
|
Q4. After receiving the first dose, premenstrual syndrome) PMS you experienced in your next period was | ||
| Worse than usual | 553 | 23.7 |
| Less bad than usual | 139 | 5.9 |
| The same as usual | 1646 | 70.4 |