39 weeks preg and sharp twinges and tightening, help?

When I'm out anywhere walking or just around the house I suddenly get a sharp twinge down in my lady section, even after I have been sitting and I stand up I get them, I would say about 3 times a day, I also get very tight feeling round the top Of my stomach just below my breasts.. I just wanted to Know if that was normal as some ppl say they get it below there belly button, the twinges do make me curl over and within 2 secs there gone, I just wanted ur opinions on what u think it could be, the midwife about 2 weeks ago said I'm 4/5 wether that helps, i just want my little girl here really as my pregnancy has not been such a good one, but I'm sure I can wait a lil longer if I have too, I also feel very sick the past few weeks and started getting diorreah this morning, thanks for any comments x