Ovarian Cysts How long should I wait?

First off, my apologies if there has already been a thread about this topic. I performed a search first to see if I could find my answer before posting, but didn't find anything.

I have a relatively new piggy. She is about 5.5 to 6 years old, according to her previous owner. Yesterday and today I noticed she is getting quite aggressive with my 2 other pigs, chasing and biting. It may have also occurred the day before yesterday, but I was working an 18 hour shift, so I wasn't there to witness. She has been like this before, but never this bad. I am assuming it is her heat cycle, but given her age, I also have to consider ovarian cysts.

When I got her I noticed she was a little pear shaped, and even asked the previous owner if she was pregnant. I was assured she was not pregnant, so I just figured that pigs come in different sizes and shapes, just like humans. Enough time has passed that I can say for certain she is not pregnant. She seemed to be really calm and at peace during lap time today.

This is really upsetting me because I hate to see my animals in distress. The other 2 pigs are being tormented and she seems uneasy. I know I am not 100% comfortable during my monthly cycle either. So my question is....should I rush her to the vet tomorrow or wait and watch? I already started documenting her "crabby days" to see if this does coincide with a cycle, but I want what's best for my animals and if there is a medical emergency I want her to get the care she needs. In the past I have been too hasty to run to the vet and have wasted money