Lightning crotch and swollen lump on the left side of groin

Hi mummies, may i seek your advice. Im at my early third triemster and wake up every morning feeling the lightning crotch sensation.. like my groin is swollen and cramped. I have also had a weird lump on the left side of my groin, which occasionally is painful but most of the time is not. It has been around for at least the past 3 weeks and i asked my gynae about it. She just told me that it is due to a strained muscle. Any advice for a FTM? Thanks!