My Period Just Finished. This Morning I Woke Up With

My period just finished. This morning I woke up with pain like electric shocks almost that would last 1 minutes then stop and come back again in waves. So I thought it was just really bad period cramps, even though I haven’t had period cramps this painful in my life. I’m only 16 years old by the way, so my period is irregular sometimes. No, I’m not pregnant. So I used a heat pack but not helping. I felt like throughing up as well? The pain isn’t going away and it’on my right side/lower belly? Please help me?