Falta de periodo, movimientos intestinales extraños y dolor inusual

Hello..

I hav missed my period by 3 weeks..I can't possibly be pregnant as have not been sexually active for about 8 months

Also for the past few months my bowel movements have changed. They used to be very regular however now I sometimes go three times a day and sometimes not at all....it's almost diarrhoea when I do go

Another weird thing is I keep getting a very strange feeling in my lower abdomen - it is like a weird tingling sensation that is quite uncomfortable and will come and go.

Does anyone have any helpful advice please??

Thanks x