What Causes Irregular Periods With Pressure Feeling In Vagina?

I am 46 and had an adnormial period in sept, thought i was not going to have a period in oct, however did start this morning, pretty light though, i am having huge pressure feeling in my female region and I feel like i need to sit on the toilet and push both vaginally and thru my rectum, the pain seems to be traveling to my lower back as well, i have had to pregnancy test and both came back negative