Blood tests should normally be quicker than 6 weeks - I hope you were offered one sample for your own test (which you should do).
If you are negative, no worries. If you are positive, you are, unfortunately, looking at a ban. Although given your circumstances you may be able to argue exceptional hardship. You really need legal advice given the impact it will have upon your life.
As for your conditional discharge, if you are over the limit, you will have to admit being in breach of your CD, but it is quite likely that the magistrates will take no further action on it - it being a totally unrelated offence.
Unfortunately, on here benefit fraudsters and drink drivers attract nothing but vitriol, so be prepared for the outpouring of vituperative remarks that this post is likely to attract.