Hello @c12341
34 weeks pregnant here, and have a PhD in whooping cough research!
In the 1970s/1980s there were concerns about the safety of the DTP vaccine (which protects against diptheria, tetanus and whooping cough). The concerns were mostly found to be unnecessary, but a new version of the DTP was developed anyway, and we've been using it in the UK since around 2004.
The current version of the DTP whooping cough vaccine has pretty much zero concerns around safety, as far as I'm aware (and I researched it fairly thoroughly when writing my PhD thesis a few months ago!). I had the booster myself back at 18 weeks pregnant, and didn't even think twice about it. The booster the NHS gives to pregnant women is the same they give to school children around the age of 5 years old, so is a very low dose - just enough to boost your immune system enough that you can pass on the immunity to baby for the short time before their own immune system develops and/or they're old enough to be vaccinated themselves.
Pros: Basically no risk at all from having the vaccine. Whooping cough is a mild illness for children and adults, but is very very serious in young babies - it can be fatal, or cause them lifelong problems. So protecting them from catching it is a very strong pro, in my opinion.
Cons: The vaccine might make your arm sore for a few days. Mine hurt for about a week! But that was the only side-effect I experienced.
I won't claim to be an expert on the flu vaccine, but can give you a relatively educated opinion on it! Unlike the whooping cough vaccine, this one is primarily to protect you, not baby. This is because pregnant women (particularly in later pregnancy, I think) are prone to catching the flu more severely than most other people. In a way, protecting yourself from the flu is also a way of protecting baby, because if you are severely ill, that is surely not very good for the baby either - I've read that it can even lead to giving birth prematurely or, in earlier pregnancy, miscarriage.
Pros: Again, very little risk. There's a chance this year's vaccine may not be very effective (we never really know until the flu season gets going), but even then it wouldn't do you any harm. It will protect you and your baby in what could be a very busy winter for the NHS - we all need to stay out of hospital as much as we possibly can, so the hospitals don't get overwhelmed.
Cons: the flu vaccine can make you feel a bit unwell for a couple of days afterwards. It CANNOT give you the flu, just mild flu-like symptoms for a relatively short period of time.
I'm getting my flu vaccine at the weekend.
Sorry for the giant wall of text, but it's rare someone asks a question here which I'm so well poised to answer!