Weight fluctuation

Good morning everyone =) I am 27 weeks pregnant and thus far have gained 1 lb a week since week 13. Last week I bought a scale, and I have been weighing myself every morning. My weight changed every time. I started at 128.4 on Saturday, which stayed the same until Tuesday. Then on Wednesday I was 131, thursday I was 130, friday and Saturday I was 129.6 and today I am 131.1. Does this happen to anyone else? I weigh myself as soon as I wake up, and sometimes after I use the bathroom. Thank you so much!