I break out before every period. Can skincare prevent it completely?

I would not promise complete prevention. Tracking the timing can help you explain the pattern when you seek advice. A repeated monthly pattern can be useful information for a medical provider if the breakouts are deep, painful, or leaving marks.

Cycle-related breakouts may need more than skincare

If it is repeatedly painful or scarring, a dermatologist can discuss treatment options; keep the everyday routine manageable rather than adding a new strong product every month.