To claim JSA, take the phone and ring 0800 055 6688 now (3 first days of claim are unpaid). Have ready your P45 and details of your bank account. It takes about 20 minutes.
Nothing to fill. All done by adviser.
Don't forget to say that you are available for work (anyway it is a charade...as no employer in the UK or beyond will hire you being 20 weeks pregnant... and anyway in 10 weeks time you'll be getting your MA... but that's the way it is...).
The adviser will give you an appointment at your local JC in 3 days time (maybe Monday?).
On Monday, at the JC, they will give you a transcript of your phone conversation for you to check, ammend if necessary, and sign.
Then, you'll be given another appointment to sign on for the 1st time (maybe the day after maybe in 2-3 days).
In 10 days or so, you should receive your payment.
Regarding the MATB1, I haven't completed yet, but midwife gave it to me yesterday and all you have to complete is your name, address, and NINO. It couldn't be easier.