My girlfriend never climaxes when we have sex. Should I be worried?

It is perfectly normal to want to give pleasure to our partners. Sex is an important bonding moment for many individuals/couples so it is normal to question whether you are any match to her previous partners, or to feel worried, especially if she had mentioned herself that she had experienced orgasms before with her ex/exes. Let's keep in mind that we are always getting to know someone better and exploring what they like and dislike, so an open communication is extremely important. People don't come with an instruction manual so you learn and improve together as you go along.