Just need to vent 😒

I'm almost 23, in a relationship for 5.5 years, waiting very impatiently on my ring 💍. I am on the pill, not intending to get pregnant but won't be the end of the world if it happens (very slim chance, I know). But this month, I KNOW I ovulated. Just as I did before the pill. I also know the pill I use prevents pregnancy in 3 different ways. However, my body has been sooooo weird. I have been nauseous for a day or two, not hungry at all (usually I am ravenous before my period), bloated like a balloon, and extremely irritable today. Period is due Wednesday, but I'm so curious. :/ why do pregnancy symptoms have to be the same as PMS???!?!??