cramps not aches (early second trimester)

Isabella

15 weeks along (heart baby's heartbeat the other day and my OB said the baby was healthy). today i have been having short, minor cramps (right where baby is) for about an hour. the cramps only last a second and are between 2 to 10 minutes apart. no bleeding or spotting. wondering if this is something I should be concerned about or if it is normal. (unable to call my doctor as its a holiday.)