Is my cat going into labor?

We don't know exactly how long she's been pregnant but we know it's around a month and a half or more. It's 9:am and ever since 3am she's been meowing A LOT more than usual and she can't seem to get comfortable. She was being very affectionate earlier and i suspected something so i put her in the box i set up for her and now she's laying in there and still can't seem to get comfortable. She's also breathing kind of hard but not panting.. Is she going into labor?