Husband on diet pills..,

So we planned on trying to conceive after summer. This week is my first ovulation after summer. However, husband trying to lose weight and was prescribed phentermine (diet pill) to help. (Under stricter watch of Dr). I mentioned to him tonight about trying and he mentioned his diet pill. Things I've googled are only women related that you shouldn't take while pregnant (duh) but any info with male on it TTC??? I'm against it but he's only on it for another month. Don't know what to do. Do I still try this week or wait another month?!