While I'm not a doctor, I can tell you some positive things. First, from receiving a bj, there is nothing you could have picked up at all that would be transmittance to your 4 month old sister or anyone else by touch std wise. From a BJ, common risks are syphilis, genital herpes (hsv 1 or 2), chlamydia and gonorrhea are also possible but I believe less likely. Another possibility is trochonomiosis but that's less common in men I believe.
No std should produce symptoms next day, earliest would be within two days generally but that's still quick. To know for sure if you picked anything up you'd want to have an std screening but you'd need to wait some time before many stds would be noticed. That ranges anywhere from generally a few weeks to a few months depending on the std you want checked.
Based of the scenario, I'd expect the flu to be the likely cause but a doctor should be able to confirm that now or at least give some input.
Of the stds above the only one to produce flu like symptoms is herpes but it wouldn't happen that quickly.
Just for Additional Info The Symptoms I had :
Shortness of breath
Pressure on Stomach
Groin Itch / Irritation ( this one happen before sexual exposure/ probably Jock Itch)
So far , There is no symptoms in my genital except for groin itch / irritation , there is no pain when urinating ( normal )
No STD would cause shortness of breath or vomiting/nausea.
I'm not sure if you mean your actual stomach when you mention the pressure, or if you mean your lower pelvic area, or what, but if you mean your actual stomach, no STD causes that, either.
As John said, no STD would give you symptoms this quickly. The absolute minimum is 2 days, and that's not that common.
You need to see a doctor if you have a fever and it's still lingering, and you have shortness of breath. No STD causes these, but something is happening, and you need to find out what.