Given the fact that you are young and it sounds relatively healthy, the likelihood that this is something serious is pretty low. Nevertheless, you are right to want to get it checked out and I would recommend that you get in to see your primary care doctor
or your OB GYN doctor as soon as the weekend is over.
The most likely scenario is that you over-exercised, and in that setting are experiencing some muscle soreness and fatigue, which is being amplified by the fact that you are also pregnant. While you are waiting to see your doctor, make sure to get plenty of rest and drink lots of fluids.
If you develop any worsening symptoms, such as worsening fatigue or muscle pain
, then you could go to an emergency room for a more immediate evaluation. You should definitely go to an emergency room if you develop any shortness of great, chest pain, palpitations, or trouble breathing, as these could be signs of a more serious problem.
On the other hand, if this remains just as feeling tired and sore, then you will probably be ok getting in to see your doctor as soon as you can next week.