monthly expenses after marriage

Monetary transaction between a wedded couple is mutual there is no specific rule of law prescribed for it, wife can legally ask for maintenance when she opts for a decree of divorce. You should convince your husband to give you some monthly allowance however if he does not agree and if you are in dire need of money the only option is to seek divorce and monthly maintenance, the choice is entirely yours. 

Yes, Law cannot take care of matters in mutual trust. Law can interfere when mutual trust breaks down.

125. Order for maintenance of wives, children and parents.

(1) If any person having sufficient means neglects or refuses to maintain-

(a) his wife, unable to maintain herself, or

If you feel being necglected or do not get proepr maintenance just file the complaint, but be careful that may strain your normal married life.