Not eating=Late period?

I’ve been sick and haven’t been eating nearly enough, less than 1,000 calories a day, for sure, and I’ve lost around 5 pounds in less than two weeks. I have a pretty irregular cycle anyway, but it tends to say anywhere between 31-45 days. The last couple months it has definitely stayed in the 31-35 day range though. It’s hard to pinpoint exactly how late I am, if I’m late all all. But compared to what my cycle has been recently, it’s 1-5 days late.

I have taken 2 tests, both very negative. No signs of period coming. So I am wondering, can not eating enough cause delayed or missed periods?