Hi, Hope someone can help

Hi I am currently waiting on a reply from my uc50 form. I was on jobseekers and have handed in sick notes from august I handed in my 13weeks sicknotes and was told I couldn’t had in anymore and had to apply for universal credit to get the sick element as I can’t apply for the old sick as all new claims have to go through universal credit. I moved to universal credit in November and waiting on my uc50 form i waited to March for this. I also handed in another sick note which ran me to April so they have had sicknotes from august to April for me. I am just wondering if I get accepted to me able to claim sick under universal credit when will my claim get back dated from. I have asked advisor with no help. Should I not of received uc50 straight away as I had to go on universal credit due to long period of sickness and I already had all my sick notes in? Sorry for the long question it’s just really frustrating me.. thank u in advance to anyone that can help x