Nausea is killing me

I just want to lay down and cry cos it's frustrating. It's very recent and not at all daily, my mood tracker shows that on average I have 2 yuck days a week...
I have a question... do the side effects of you BP meds set in as soon as you go on them, as soon as they start working, or 2 months into taking them? I've been on my combo since July and have recently started this nausea battle... Beside the nausea I'm doing GREAT, but am I even on the right track here?
Thanks in advance