DNA tests will give you the information you need.

It is normal for a child not to look like the parent … the genes can come from wayyyy down the line of an ancestor.

I believe its possible to do an at home DNA test. Like Ancesty.com or something similar.

Oh lord, newborn babies look like everybody and nobody. And it's perfectly normal for a child to resemble one parent and not the either, or resemble neither parent and look like a distant ancestor or even the next-door neighbor despite no blood relationship.

It's an old, hurtful myth that a baby looks like its father. It's the reason many men give to justify mistrusting the mothers and abandoning the child.

Another old, hurtful myth is that you can accurately foresee what your child's eye, hair, or skin color will be. Surprise! Genetics aren't that simple. Even two blue-eyed people can produce a brown-eyed child.

If you don't trust your son's mother, then tell her and demand a DNA test. And be prepared to deal with the ugly fallout when the baby turns out to be yours.

DNA test is the only way to be 100% sure. Baby's eye color is not real until they are about 3 months old.

Grow up. Yes, it is very normal for a baby to not look much like either parent. It is also normal for a baby to look like either one or both parents. Babies look mostly like babies. If you think you might not be the biological father of the child, get a DNA test. That isn't rocket science.

You can start with finding out what you are your son's blood types are. From there you can actually do a paternity test.

Ah, you're buying into the myth that all newborns look like their father?

That is just that: a myth. Newborns mostly look like newborns. And it's human nature to look for expected similarities, that is why people think he looks like you. You on the other hand expect to see evidence that your girlfriend cheated, so that is what you see when you look at your son.

In other words: it's your suspicions that make you see the other guy in your son's features, not your son's appearance that makes you suspect.

You can get a paternity test done. That way you can be sure once and for all. Get it done soon, before this doubt destroys your relationship. You don't want to break up over this and then find out the boy is your son after all.

Of course it's normal. I have five kids, two of them look absolutely nothing like me. In fact, one is the spitting image of one of my best friends and her boyfriend combined.

Either you trust her or you don't. You can request a DNA test. If she didn't cheat and you keep questioning her, she'd almost certain to no longer be your girlfriend anymore though. I wouldn't take well to my husband questioning me, especially after I'd flat out told him I didn't sleep with anyone else. I'd take the DNA test in a heartbeat and then sue him for everything he had when I was proven right and he was proven paranoid.

It is normal. Mine looked like neither of us but looked like an alien until he was 2 months old. If you have suspicions a DNA test wil solve it.

Well, this relationship clearly isn't working, regardless of whether or not your girlfriend got pregnant by someone else. You suspect that this baby might not be yours, and regardless of the outcome that is a huge red flag.

If you don't trust her then you shouldn't be with her. Meet with a lawyer to discuss custody and child support payments, then have a talk with your girlfriend about how to co=parent as single people.

If you trust her then keep your mouth shut.

Babies don't always look like both parents. My daughter looks exactly like my husband and almost nothing like me, even though she's clearly my child since I gave birth to her. Take a biology class.