Are you on a 9 or 10 period day? If you're not, and they're making you give up your conference period time, that is absolutely illegal. Call your teacher association representative.
You are required per Texas state law to be given 450 minutes of planning time every two weeks in blocks of not less than 45 minutes. This cannot coincide with your duty free lunch, nor can you be asked to cover classes or do pullouts during that time.
Time "on the clock" without students may NOT be used to cover that 450 minutes - for example, if you are required to be "on clock" at 7:30 and the school day starts at 8:15, that 45 minutes does NOT count as your conference time.