Could Severe Cramps Be Due To Implantation?

hi I am 33 yrs old, TTC for 4 yrs. I have PCOS, Clomind failed on me so had to go for Gonadotropin injectibles. ovulated at a high dose of 225+300 IU. IUI was performed on 30-May-14 morning. had extreme heaviness and cramps at night. now after 4 days, again I am feeling cramps while sitting or standing. is this implantation pain or I am just being too optimistic? i feel tired, sleepy and irritated most of the time. but there is no bloating. my breasts r sore when i touch it but not too much but yes it pains. is there any chance that I am pregnant? is it too early to say this? are all these symptoms normal after an IUI?? plz guide.