What reason would two 29 year olds have for not being able to get pregnant after 9 months of trying?

there are literally hundreds of reasons why it could take 9 months or more to conceive. If you are worried about fertility it is best to have appropriate tests then if there is a problem you know about it.

However it can take much longer than 9 months to get pregnant, it may feel like forever but it really isn't. A few things that can slow down the process are if the woman has been taking the contraceptive pill for a while as it can take several months to fully leave her system. Other reasons may be either person smoking, drinking alcohol or caffeine. Try to remember that caffeine is present in other place than coffee and tea. There is also caffeine in some carbonated drinks and chocolate. The main thing is just to try and relax and not to stress. worrying about things doesn't change them