Strange inconsistency in my period.

I'm 26 and TTC baby 2. 
I have always had normal on time very consistent periods. I'm so confused. 
I started spotting on Monday afternoon, 2 days ahead of schedule, it reached a medium flow for Tuesday. 
Then on Wednesday it just stopped completely. Last night while my husband and I where having sex, I began to bleed extremely heavy. And now this morning it has stopped again. 
Some one please help me with some type of explaination...