I can't decided whether or not to have sex?

Do wateva you feel is right in your heart.

I can't say that I personally advocate waiting until marriage for everyone although I do think it's a nice thought.
That being said, I don't know how old you are or anything and all that.. so it's hard to say one way or the other. If you're in high school or in your teens still, and you're not sure if you're ready AND you've only been dating him for 4 months... then I think you have your answer.
Honestly 4 months isn't a long time and if waiting until marriage is something that you had always thought about doing, then it might be better to be careful and make sure that you're REALLY sure. I think a good rule of thumb with sexual stuff is if you're not really sure how you feel about it, then don't.

Sex means different things to different people. I think you should think about what it means to you and then figure out what to do.

I should imagine the last thing you really would want on your wedding night is for the love making to be a huge disappointment, painful or even unpleasant.
Wouldn't it be nicer if you were already comfortable with love making instead of fumbling around, afraid and unsure of how to please your new husband?

You should talk to him or wait for marriage. I would wait but I haven't had my first kiss.(I want it to be on my wedding day) just follow your heart.

If its just vaginal sex that you want to keep till marriage ? There's many other things you could do . Persanlly I'd say wait till marriage of that's your thing. But if you would like to release a bit of sexual tension then explore , its just very dificult ressisting once you in that mood.

If you've been together for 4 months and haven't had sex you'e either (a) lucky he's still around, or (b) you've snagged a pathetic beta male that will never be able to please you and you'll end up playing the role of mommy to him. I personally lean toward the "b" answer.

And those acts aren't sex? You have a very narrow definition of sex: it's not only actual penetrative intercourse you know

First ? Is how old are you next I think u can Waite u can do thing that are not sex u can jerk him off u can suck him off he can eat u out he can finger u there r ways u can get him off n u can get off n u can still save ur v card for the one that conts