pregnant guppy ill or ready to drop?

I know that pregnant guppies hid when they are about to drop but I'm really worried about one of my guppies in particular, she usually hides by the filter and would never come out but now she has been completely out of sight for two days, I hadn't seen her once, I was worried she might be dead or trapped so moved the big boat I have in my tank and she was under there, when I found where she was she floated nose down and then got sucked onto where the filter sucks water but she was moving and breathing so I got the net and moved her, she then swam (quite badly, not going very quickly) along the ground back to the boat, she went under it back out of sight! she didn't look very well at all, her belly was big and square but her gravid spot is no longer black but orange (and higher up?), under her gravid spot it is really different from when I last saw her too; her tail half is as normal but it goes straight down like a step straight at her gravid spot, its really hard to explain sorry. Can someone please tell me if she is ill or just very pregnant? and if she is just pregnant when, realistically, is she going to drop and also how long it will take for her to return to normal? if she is ill what might it be and what can I do?