We buy whole milk (my boyfriend and I) and usually it goes bad a day or two before the expiration date (the 27th)

When I opened the cap it doesn't smell bad or anything, just not how it smells in the beginning. I took a sip and it tastes kinda creamy like heavy cream. Is that bad? It didn't taste bad, but I don't want one of us to get sick just because I hate throwing out stuff that isn't expired