I actually think Linda was a .............

Doug was real, but he was probably just a one-night stand or a summer fling. Then, after he goes back to college, Linda hopes that their relationship is something more, something that'll keep growing. And yeah she also embellishes their bedroom lives so Stacy is impressed and thinks Linda knows more than she does.

Probably you are right, she was just talking big to impress her friend.

So did she have trouble getting a boyfriend there at school or just wasn't interested? What do you think?

Fiancé in Chicago my ass

Thought so too. But was sizzling hot.

I don't think she was a virgin, and her relationship with Doug was real.

However....

I think she exaggerated, or downright lied about most of the details of the relationship. Like many younger girls, she thinks that just because a guy is older and at a higher level than her (college vs high school) he must be much more mature than any high school boy. So she is actually able to talk to him, and he respects her, and isn't just after one thing. And like most girls, she eventually figures out that a college guy who is dating a high school girl, he's not only probably too immature for girls his age, but a big a creeper too. And he is still only after the one thing, but he has enough experience to know that if you actually talk to a girl, and act like you're interested in what she has to say, you have a better chance of scoring with her.

At this point in the relationship, Linda was realizing that Doug was full of crap. He didn't respect her, he just wanted to nail her. And it was easier for him to get a high school girl to believe he actually respected her. And he was probably not a good lover either, which is why she struggled to answer the time question. She had built up the idea of him early on to her friend, and didn't want to have to admit that he was a loser on all fronts, and she had been duped by him.

maybe not a virgin but not really as experienced as she played out to be
aka female-Damone

You do realize this movie is a work of fiction. It was never written into the story about her being a virgin