Upper thighs aching?

Never heard of this one! But I was wondering if it's possibly a sign of early pregnancy, I haven't had a positive result yet but my husband and I have been trying to conceive & my upper thighs ache pretty bad, like I've been working out too hard or something. I've never had this before at all, and I did absolutely nothing yesterday to cause it. They've been aching since yesterday evening. Could it be a weird early symptom, has anyone had this before? Or do you think it's just a coincidence?