Irregular, late and worried. Need advice

So for quite a while my periods have been somewhat irregular, or just very short cycles. I was a part of a competitive sport that practiced Friday-Sunday with rehearsals for about 8 hrs a day. The season recently ended in late April so I haven’t been as active lately. However I’ve been trying to eat a lot healthier lately with more fruit etc. My period is almost a week late now. I’m kinda stressed about it. I’m still a virgin so I’m pretty sure it’s not a pregnancy Does this change in lifestyle seem reasonable for why it’s late?