My stomach feels funny like it's trembling i'm on my cycle now started on 29. not sure if it's connected?

Might be.: 'Trembling' would make me think GI related and not uterus/ovary but still could be a gyn issue. Does not point to anything obviously sinister if not having pain/fever and cycles are regular and not at risk for pregnancy. If recurs with future cycles then more likely uterine/ gyn related. If progressive and becomes painful then would touch base with your provider.