Ok first thing first. Do not strap a portaloo to your head. It will not be of any use there. You need to strap it closer to your errrrmmmm ……. Well I’m sure you know where. But if you are still not sure where best to put the portaloo here is one way to find out:-
1 Drink 3 glasses of water
2 do not go to the bathroom for 1 hour
3 after 1 hour sniff a small amount of pepper
4 the damp area is where the portaloo should be positioned

It’s a good idea to rule a UTI but it is more likely to be the baby causing your wee problem. Often things can improve when the baby changes position. Some good news for you is that your wee problem will not get any worse.