mum of 5 but baffled...

Toy

Hi ladies 😊 I'm a mum of 5, my youngest being 6mths old. I'm currently breastfeeding miss 6mths. We went away for the weekend of the 10th & i fed missy some custards at bedtime to fill her up whilst we were away as we tend not to feed as often as we would sitting around the house. Since coming home everything is back to normal, until this week when i noticed the clear (egg white) type mucus on Tuesday & again on Wednesday, wednesdays had a tiny streak of pink blood through it which i noticed due to it being on toilet paper when i wiped. Thursday morning i woke up to bad lower back pain & cramps in the lower abdomen. I went to the toilet only to notice blood when i wiped & figured AF had come due to me not feeding as much whilst we were away :-( to my suprise i only needed 1 pad & then the bleeding stopped. The bleeding must've only lasted a couple of hours at the most & nothing since. Does anyone have any ideas as to what the bleed was or why ?