Condom came off, should I get tested for STI's?

[earthquake-girl.livejournal.com]

So this is so embarrassing and I don't know who to talk to. I had sex with my B/F last weekend for the first time, after 10 months of dating. We used a condom. It seemed like he had problems staying erect though. I am not 100% certain he even came, though he says he did. Second time we had sex, the condom came off midway through because he was not very hard. He didn't come in me, he pulled out right away, but he was def. inside of me without the condom for a second. It was really embarrassing and we didn't really talk about it. I don't know if it was just me or what, and I was too embarrassed to ask him. The third time we used a condom, but again, he was not staying very hard and it was slipping off. It was really awkward, and we switched to oral and he did come, but it was strange because he was not very hard.
I am afraid that I got a STI from the second time. I can't stop thinking about about it, and I wonder if I should go get checked. I am so embarrassed though. And I don't know how to ask or talk to my B/F about this. I don't even want to have sex with him again right now because I'm afraid it will happen again. (The not having a very hard erection and condom not staying on thing) It's killing me because we took things slow, and I'm in love with him, but I don't know what to do, especially if I have an STI because of it. I got chlamydia three years ago from my husband and we got divorced because of it. I'm afraid my Dr. will think I'm a slut or something if I ask to get tested again. How do I talk to my B/F about this? Is there something I can do to help him stay hard? I feel so low right now, like I never want to have sex again.