Pregnancy symptoms days before period due?

have pcos and have been TTC for a few years. for about a week an a half, i’ve had upper back pain and my boobs just feel huge. I’ve also noticed very blue veins thru my nipples but they aren’t necessarily sore, just my upper chest and back. I was nauseous in the morning and some nights now but I tested negative. I also tested today and ended up having an error digital test. So now i’m wondering if I should wait until the day before vacation to test again with my last digital? Or go ahead in the morning since i’ll be around 3-4 days before my period should be coming.