Best way to comfort partner during mood swings periods

Hi my partner keeps getting mood swings randomly and feels distant. Some days she’s fine some days she’s really off. I ask if I’ve done anything wrong she says no stop asking. She gets really irritable about everything, she’s on antidepressants and implant , normally notice it before a period but sometimes happens randomly during a month, I’ve done nothing wrong but feels like I have, feels like she’s giving me cold shoulder short reply’s to things I ask, and just feels like not interested. But then she says she’s totally fine with me and I know I’ve done nothing wrong at all, she has depression and bad anxiety, but today really feels the worst like I’ve upset her but I haven’t,

Any idea what I should be doing through these times should I give space, I take it affection is not wanted or to be bothered but I could be wrong, I’ve bought flowers chocolates all sorts in past during that time of month, still have the off feeling, I just have to ride it out for a better day, but if there is a magic trick I cando please let me know ladies or any men that know what’s best todo during those moody feeling low moods.