What Causes Stomach Cramps And Missed Period In A 46 Year Old?

I have cramps period like. I haven t had a period since July I have had a couple of bouts of feeling nautious. I have back ache and a stich like pain on my sides. My teeth hurt and are very sensitive. I am so sure I can feel movement in my womb. I am peeing more frequently and I wake at odd hours Hungary. Despite a very clean normal healthy diet I ve gained weight and my jeans no longer fit. I ve done 6 pregnancy tests all negative. I m 46 and was beginning to show signs of perimenopause I also have a clean smelling small white discharge I m 90% sure I m pregnant but the tests show negative they were all home pregnancy tests Any advice?