Confused

Not sure if anyone can help me and hubby have been ttc baby no5 since March. I came of the pill cerrazette on 10th March. Last night while been intimate hubby said my boobs were leaking a little. I went to the bathroom and yes both were leaking a little clearish fluid did a test this morning and it's negative knew it would be as was on my period last week. Had nothing since it was just last night Worrying myself silly it is something serious has anyone had or heard of this before and know what it could be and advice or help would be great.