The reason for your physician's recommendation is that some antibiotics may affect the efficacy of hormonal contraception. However, this is a weak effect even when present and thus the addition of a back up method (even if not so effective in its own right) should be sufficient. Spermicides (available over the counter in many forms) should fill this role well.

Therefore, we see no reason to delay mikveh for two weeks. Even if you do not find spermicide to be a sufficient back up, you can immerse in the mikveh on time to enable other forms of closeness, resuming relations when you both agree you are ready.

Please write back with any further questions.

Refuah sheleimah!