I've recently just had something similar to this I had sharp pain shooting down my back left side and the bottom of my left side of tummy, also experienced cramps and bleeding with this I went EPU and they said my left ovary was the cause to it as it was a little bulky but was doing it's job. If you ever get concerned I would definitely just speak to your midwife as most pains and ache are normal in pregnancy but it's best to ease your mind.