Hmm, susah nak tahu exactly la, banyak factor boleh affect period timing like stress, diet changes, or hormonal shift kalau start minum susu baru. A few of my mum friends pun pernah experience delayed period after trying new supplements or dairy products, tapi it's hard to say if it's directly connected or coincidence. The cramping part yang concern sikit, so I'd suggest check with your gynae just to be safe, terutama since your cycle biasanya regular, better to rule out any underlying things rather than guess. In the meantime, observe if period comes within the next couple weeks or if the cramps get worse, then go from there okay.