Feeling emotional

I'm currently on the road heading out of town with the guy I've been dating for 3 1/2 years. A couple of days ago I switched to the Nuvaring birth control and I noticed that I've been feeling emotional, nauseous, & im slightly cramping today. Should I inform him of this when we arrive to the hotel or should I keep it to myself? Because I highly doubt I'll be in the mood for sex... I'm afraid that I'll just ruin the vibe & the fun this weekend.