Can you have two LH surges?

Unknown. you really shouldn't need one after you had the first successful one.
Yes. The LH surge is different in different women. Some women have a very short surge that only lasts one day. Others have a longer surge that lasts 2 or 3 days. However, a third group has a bimodal surge that peaks, drops a day or so, and then peaks again. Therefore you can have 2 positives on your LH surge testing. However, the important one is the first positive, time IUI with that one.