Poop changes!

Our lo is nearly 9 months, started weaning her at just over 6 months, she has bit of solids at breakfast and then lunch or early evening, she also has up to 100ml formula a day sometimes much less or none, she still also has 700-900ml breast milk. her poops started to change to bit thicker and less frequent few weeks ok, felt like normal transition but now she suddenly only goes every other day and last few days it's just been one formed blob, just seems unusual as she's having so much breast milk still and I think she might be bit uncomfy and struggles/gets upset when pooping at times but unsure if I'm just over worrying, difficult to tell what is normal esp re quantity when it looks so different as a solid poop! thanks all