Period question

Lex • 30 and TTC

So I haven’t had a period in almost a year because I was on medication to put my ovaries into hibernation because I was going through cancer treatments. Before that I only got 2 periods and before that I was on mirena for like 3 years and never got a period so I’m kind of out of the loop here and confused. I just got my first period in almost a year and it’s SUPER different I assume because it’s only the first one back. But I just took my tampon out and it had blood on it (no duh) but it also had a think white mucusy on it. Maybe I’m just being dumb or just forgetting how periods work please don’t judge because I also have chemo brain so I forget stuff easily but can someone explain this to my 28 year old self? Otherwise I can ask my doctor tomorrow when I see him after radiation.