Can someone help me please

My fiancé and I haven't had it easy. 3 loses. 2 miscarriages and 1 ectopic. This happened because my uterus was misshaped and I had no idea. Cause why would they tell me when they did my ultrasound for my first baby?! Ugh. Anyway... I had the surgery to fix my uterus and it's all normal now. I'm 15 days dpo and women I know you know what this feels like... I was letting my dog outside and felt something coming out of vagina. Thought maybe my period started? It was due yesterday according to my other app but this one says 19th so who knows. Anyway, so I felt it and went to the bathroom and looked. Nothing in my underwear, so I peed and wiped. In the toilet paper, was a glob of snot like (gross) mucus type stuff. No blood or anything. I'm guessing that's what I felt?? I took a first response pregnant test at 7 & 8 days dpo and they were both negative not even a very faint line. I've had weird cramps, not like normal period ones. Had some twinge type, pulling, prickly cramps for a while. They've gone away and I'm SUPER gassy (sorry, lol), and something just feels different. I hope I'm not just tricking my body into thinking I feel these things cause I WANT to. But does anyone know what this glob snot looking stuff is? I didn't post a pic cause I don't wanna gross anyone out! Also should I test again or just wait till the 19th since this app says that's when my period is due? My cycles are a few days apart each time. One month was 27 and one was 30 so... not sure :( but I'm so impatient!!