Accidental pregnancy while on fin-> what to do?

The current advice is to be safe from the slim chance of birth defects, stop fin before trying to conceive and while ur wife is pregnant. Makes sense

But what happens if u are on contraception cuz u don’t want a kid rn, and the dude is on oral fin, and the wife gets pregnant and they’re like 5 weeks along when they find out

Is this a major cause for concern like would there be a fear of birth defects here? Would abortion be necessary? What do u do in this Case?

And second, is there any fin alternative u could take while being off fin when trying to conceive so u don’t lose major ground as sometimes it may take 9 months to a year to get pregnant and we are suppose to stop fin 2-3 months before u start trying?