If the repairs are not essential he does not have to fix it. Someone will come from Housing and talk to your neighbors to determine how many dogs and people are there. The landlord can say he has seen unauthorized people. Why jeopardize your Section 8 status with extra people and dogs?
Your lease can be terminated for violations definitely but worse, you can then be evicted and also lose your voucher. To be in good standing with Sec 8 means you have not violated their rules. If you not in good standing you will be evicted, lose your voucher, be prosecuted for fraud, repay all the money they gave for rent subsidy.
3 months pregnant is your problem. Your other question about your husband I answered. You should move before you get evicted, then you keep your voucher and let your husband move back in after you find another place. As I said, leave before you get evicted. Whether your kids eat is not the landlord's problem. If you follow the Housing rules and dont cheat you would not be in this situation.