If you get pink eye during pregnancy, you need to see a physician who will be able to prescrible antibiotics if necessary depend on the type of pink eye you have. There are some antibiotics that can be used safely during pregnancy, but some other antibiotics may have side effects on pregnant women. So you are not allowed to apply antibiotics which is bought from the drug store for your pink eye during pregnancy. You should consult your doctor instead.
To be safe, i think you shall not use your husband antibiotics. You'd better ask an eye doctor that if you can use it during pregnancy before you take it. The doctor will determine what type of pink eye you have contracted and what measures you can use to treat, or use antibiotics, if necessary. I think it is unwise to take risks of using the antibiotics that your husbands use.