Yeah I've had these too and still get them, if I do too much. It's a sign for me to slow down and rest for a day or 2.

If I stand too long, or spend hours doing house work etc I'll get them. One on one side and one on the other. Sometimes they linger around too, they aren't very nice But mine have never hurt bubs, and feel like I have pulled a muscle so I believe I just strain that whole area too much.

Hope it feels better soon.