Spotting and I am scared

So I am about to turn 47 in a couple of weeks. Now that I look back, I think my perimenopausal symptoms started about 4 years ago with noticeable increased anxiety and the biggest clue, my periods went from every 28 days to every 17 to 20 days. This past year, missed periods, spotting only periods, spotting in between periods (always brown stuff), 1-2 day very light periods and now this month, I have been spotting for a couple of weeks. My last period was on December 16 (lasted 1 day), so not really a period. On December 28 after being intimate with my husband, I alarmingly noticed brown/pinkish discharge right after, and this happened later in the week also. After further investigation, I realize that the few times I go to the bathroom and wipe (sorry TMI), there is always a tiny bit of brownish stuff on the paper but it never shows up on my undergarments. I am not due for another period until probably later this week so I am really worried about this discharge and what it could be. I went to the doctor last week and was able to see a nurse practitioner who didn't seem to be worried but ordered a transvaginal ultrasound and bloodworm to check my hormones. I haven't gone for bloodwork yet but I did get the ultrasounds since I was SUPER anxious. Happily the ultrasound was completely negative. I have a really good friend who is a radiologist and I was lucky enough to have him be there that day and he even came into the room to reassure me that everything looked fine. My endometrial stripe or lining is 4 mm so I think that is good. I see my regular GYN doctor next Friday for my annual pelvic exam so I guess after that I will feel better. My last 20 Pap smears have always been completely negative including a negative HPV DNA test. My concern and worry is that I still have this brownish stuff that is still there when I wipe only and after sex. Has anyone had this ever happened to them? As far as the brown discharge is concerned, I have had it MANY times in the past right before my period. My period is still a ways away and this has been happening for a week already, I am worried........ Any words of encouragement or experiences?