Pelvic pressure/pain ?

Brittney • Life is beautiful! I'm 21 years old, in love, having a baby. What more can i ask for.
I'll be 19 weeks this Saturday and today I started feeling pelvic pain/ pressure. I have felt it before but not as quites as bad. Been couple weeks since the last feeling of pressure. Does anyone else have this.  I'm sure we all get it but just wanting some thoughts on causes and what might help relieve some of the pressure