Please help. I don want to just be over reacting, but this is my first child so I have no idea what…

Please help. I don want to just be over reacting, but this is my first child so I have no idea what to expect. I am almost 31 weeks. I started to get these sharp pains in my stomach, they are just sporadic and all over the place. there isn't really any pain in my lower areas. mostly just my stomach/bump. could these be contractions or Braxton Hicks. I'm just nervous. I am home alone and not sure what I should do if it keeps happening.