How To Check If Illumina Fastq Is Single Or Paired End With Minimal Sequence Id

Hi all, I am trying to check if a FASTQ is single or paired end. From wikipedia I saw that default format has to be like this:

@HWUSI-EAS100R:6:73:941:1973#0/1

but in my case the sequence id is like

@HWUSI-EAS100R:6:73:941:1973

with missing # part.. Can I assume that it is single end? I could not find a good source to learn from about it.. can you also point me to something like this? Thanks